I. Introduction

Obligations are among the most important concepts in Philippine civil law. They govern contracts, debts, damages, property relations, family transactions, business dealings, employment arrangements, commercial agreements, and countless everyday legal relationships.

Under the Civil Code of the Philippines, an obligation is a juridical necessity to give, to do, or not to do. This means that when a valid obligation exists, the person bound by it may be compelled by law to perform the prestation owed.

The law on obligations answers fundamental questions:

What must be performed? Who must perform it? For whom must it be performed? When must it be performed? How must it be performed? What happens if performance becomes impossible? What remedies are available in case of breach?

The classification of obligations is essential because the legal consequences differ depending on the kind of obligation involved.

II. Legal Definition of Obligation

Under Philippine law, an obligation is a juridical necessity to give, to do, or not to do.

This definition contains several important ideas.

First, an obligation is juridical, meaning it is recognized by law. It is not merely a moral, social, or religious duty.

Second, it is a necessity, meaning the debtor may be legally compelled to perform.

Third, the object of the obligation is a prestation, which may consist of:

giving something;
doing something;
refraining from doing something.

Thus, obligations are legally enforceable duties.

III. Essential Elements of an Obligation

Every civil obligation has four essential elements:

1. Active Subject

The active subject is the person entitled to demand performance. This person is also called the creditor or obligee.

Example: If Ana lends Ben ₱100,000, Ana is the creditor.

2. Passive Subject

The passive subject is the person bound to perform. This person is also called the debtor or obligor.

Example: Ben, who must repay the loan, is the debtor.

3. Object or Prestation

The prestation is the conduct required from the debtor. It may be:

to give;
to do;
not to do.

Example: Paying money, delivering a car, constructing a house, or refraining from opening a competing business.

4. Juridical or Legal Tie

The juridical tie is the legal connection binding the debtor to the creditor. It is the reason why the debtor may be compelled to perform.

The juridical tie may arise from law, contract, quasi-contract, delict, or quasi-delict.

IV. Sources of Obligations

Before discussing the kinds of obligations, it is important to identify their sources. Under the Civil Code, obligations arise from:

Law
Contracts
Quasi-contracts
Acts or omissions punished by law
Quasi-delicts

These are the recognized sources of civil obligations.

A. Obligations Arising from Law

Obligations arising from law are not presumed. Only those expressly determined in the Civil Code or special laws are demandable.

Examples include:

obligation to pay taxes;
obligation to support certain family members;
obligation of employers to comply with labor standards;
obligation to pay damages in certain cases;
obligation of co-owners to contribute to expenses of preservation.

B. Obligations Arising from Contracts

Contractual obligations arise from agreements between parties. Once a contract is perfected, the parties are bound not only to what is expressly stipulated, but also to all consequences that are in keeping with good faith, usage, and law.

Example: A lease contract obliges the lessor to allow use of the property and the lessee to pay rent.

C. Obligations Arising from Quasi-Contracts

Quasi-contracts are lawful, voluntary, and unilateral acts that give rise to obligations to prevent unjust enrichment.

The two classic examples are:

Negotiorum gestio – voluntary management of another’s abandoned or neglected business or property without authority.
Solutio indebiti – payment received by mistake when there is no right to demand it.

Example: If Juan accidentally pays Pedro ₱50,000 thinking he owes Pedro money, Pedro must return it if no debt exists.

D. Obligations Arising from Crimes or Delicts

When a person commits a crime, civil liability may arise from the criminal act. The offender may be obliged to make restitution, reparation, or indemnification.

Example: A thief who steals a motorcycle may be criminally liable and also civilly liable to return the motorcycle or pay its value.

E. Obligations Arising from Quasi-Delicts

A quasi-delict occurs when a person, by act or omission, causes damage to another through fault or negligence, without a pre-existing contractual relation between the parties.

Example: A driver who negligently hits a pedestrian may be liable for damages.

V. Primary Classification: Obligations to Give, to Do, and Not to Do

The most basic classification of obligations is based on the nature of the prestation.

VI. Obligation to Give

An obligation to give is an obligation to deliver a thing.

The thing may be:

determinate or specific;
generic or indeterminate.

A. Obligation to Give a Determinate Thing

A determinate thing is one that is particularly designated or physically segregated from all others of the same class.

Example: “I will deliver to you my Toyota Fortuner with plate number ABC 1234.”

In obligations to give a determinate thing, the debtor has several duties:

to preserve the thing with proper diligence;
to deliver the thing itself;
to deliver the fruits of the thing, when applicable;
to deliver accessions and accessories;
to answer for damages in case of breach.

B. Duty to Preserve the Thing

Before delivery, the debtor must take care of the thing with the diligence of a good father of a family, unless the law or agreement requires another standard.

Example: If a seller agrees to deliver a specific horse next week, the seller must feed and care for the horse until delivery.

C. Right to Fruits

The creditor has a personal right to the fruits of the thing from the time the obligation to deliver arises. However, the creditor generally does not acquire a real right over the thing until delivery.

Fruits may be:

natural fruits;
industrial fruits;
civil fruits.

Civil fruits include rent or income derived from property.

D. Accessions and Accessories

The obligation to deliver a determinate thing includes the obligation to deliver its accessions and accessories, even if they are not mentioned.

Accessions are additions or improvements produced by or incorporated into the thing.

Accessories are things joined to or included with the principal thing for its use, perfection, or enjoyment.

Example: The sale of a specific car generally includes its keys, standard tools, and installed accessories unless otherwise agreed.

E. Breach in Obligation to Give a Determinate Thing

If the debtor fails to deliver a determinate thing, the creditor may compel specific performance, if possible, and may also recover damages.

If the thing is lost due to the debtor’s fault, the debtor may be liable for damages.

VII. Obligation to Give a Generic Thing

A generic thing is identified only by its class or genus.

Example: “I will deliver 100 sacks of rice.”

In obligations to give a generic thing, the general rule is that the loss of the thing does not extinguish the obligation because genus never perishes.

Thus, if the debtor’s 100 sacks of rice are destroyed, the debtor may still be required to deliver another 100 sacks of rice of the agreed kind and quality.

The creditor may ask that the obligation be performed at the debtor’s expense.

VIII. Obligation to Do

An obligation to do requires the debtor to perform an act or service.

Examples:

to build a house;
to repair a vehicle;
to render accounting services;
to paint a portrait;
to teach a course;
to transport goods;
to perform under a service contract.

If the debtor fails to perform, the creditor may generally have the act done by another at the debtor’s expense, unless the obligation is purely personal or requires the debtor’s special qualifications.

If the debtor performs the act poorly, it may be undone at the debtor’s expense.

If the debtor violates the obligation by delay, fraud, negligence, or contravention of the tenor of the obligation, damages may be recovered.

Personal Obligations to Do

Some obligations to do are personal in nature.

Example: A famous singer agrees to perform at a concert. The creditor cannot compel another singer to substitute if the contract specifically required that artist.

Courts generally cannot compel a person to perform a purely personal act through physical coercion, but damages may be awarded for breach.

IX. Obligation Not to Do

An obligation not to do requires the debtor to refrain from an act.

Examples:

not to build above a certain height;
not to disclose confidential information;
not to compete within a certain area and period, if valid;
not to enter certain premises;
not to use a trademark;
not to disturb another’s possession.

If the debtor does what was forbidden, the act may be undone at the debtor’s expense if possible, and damages may be recovered.

Example: If a landowner promises not to build a wall blocking a neighbor’s easement but builds it anyway, the wall may be ordered removed, subject to legal requirements.

X. Pure and Conditional Obligations

Another major classification concerns whether the obligation is subject to a condition.

XI. Pure Obligations

A pure obligation is one whose performance does not depend on a future or uncertain event, or upon a past event unknown to the parties.

It is demandable at once.

Example: “I promise to pay you ₱50,000.”

If no period or condition is attached, the obligation is generally immediately demandable, subject to the nature of the obligation and applicable law.

XII. Conditional Obligations

A conditional obligation is one whose effectivity or extinguishment depends upon a future and uncertain event, or upon a past event unknown to the parties.

Example: “I will give you ₱100,000 if you pass the bar examinations.”

Passing the bar is a future and uncertain event at the time the obligation is made.

Conditions may be classified in several ways.

XIII. Suspensive and Resolutory Conditions

A. Suspensive Condition

A suspensive condition gives rise to the obligation only upon fulfillment of the condition.

Example: “I will sell you my land if I am transferred to Cebu.”

Until the transfer happens, the obligation is not yet demandable.

B. Resolutory Condition

A resolutory condition extinguishes an already existing obligation upon fulfillment of the condition.

Example: “You may use my condominium unit until my daughter returns from abroad.”

The obligation exists immediately but ends when the daughter returns.

XIV. Potestative, Casual, and Mixed Conditions

A. Potestative Condition

A potestative condition depends upon the will of one of the parties.

Example: “I will pay you if I want to.”

If the suspensive condition depends solely upon the will of the debtor, the obligation is generally void because the debtor’s promise is illusory.

However, if the condition depends upon the will of the creditor, or if it is resolutory, different rules may apply.

B. Casual Condition

A casual condition depends upon chance or the will of a third person.

Example: “I will pay you ₱100,000 if it rains tomorrow.”

C. Mixed Condition

A mixed condition depends partly upon the will of a party and partly upon chance or the will of a third person.

Example: “I will give you a bonus if you close a deal with Company X.”

The condition depends partly on the efforts of the person and partly on the decision of Company X.

XV. Possible and Impossible Conditions

A. Possible Condition

A possible condition is one that can legally and physically happen.

Example: “I will donate ₱50,000 if you graduate from college.”

B. Impossible Condition

An impossible condition is one that cannot happen physically or legally.

Example: “I will give you my car if you make the sun rise in the west.”

Impossible conditions generally annul the obligation dependent upon them when they are attached to an obligation to do an impossible thing.

However, in some dispositions, especially in donations or succession, impossible or illegal conditions may be treated differently depending on the governing rules.

XVI. Positive and Negative Conditions

A. Positive Condition

A positive condition requires that an event happen.

Example: “I will pay you if the building permit is approved.”

B. Negative Condition

A negative condition requires that an event not happen.

Example: “I will pay you if no case is filed against the company within one year.”

The rules on fulfillment differ depending on whether the condition is positive or negative.

XVII. Divisible and Indivisible Conditions

A condition may also relate to whether partial fulfillment is possible.

Example of divisible condition: completion of several phases of a project.

Example of indivisible condition: passing a licensure examination.

The effects depend on the parties’ agreement and the nature of the obligation.

XVIII. Constructive Fulfillment of Conditions

A condition is deemed fulfilled when the obligor voluntarily prevents its fulfillment.

Example: A seller promises to sell land if the buyer obtains financing. The seller then refuses to provide required documents solely to prevent the buyer from obtaining financing. The condition may be deemed fulfilled.

This rule prevents bad faith.

XIX. Obligations with a Period

An obligation with a period is one whose demandability or extinguishment depends on a future and certain event.

The key difference between a condition and a period is certainty.

A condition is future and uncertain. A period is future and certain, although the exact date may sometimes be unknown.

Example: “I will pay you on December 31, 2026.”

Example of certain event with uncertain date: “I will pay you upon the death of X.” Death is certain to happen, but the date is uncertain.

XX. Suspensive Period and Resolutory Period

A. Suspensive Period

A suspensive period delays the demandability of an obligation.

Example: “I will pay you on June 30, 2026.”

The obligation already exists, but the creditor cannot demand payment until the period arrives.

B. Resolutory Period

A resolutory period terminates the obligation upon arrival of the day certain.

Example: “You may occupy the apartment until December 31, 2026.”

The right exists immediately but ends when the period arrives.

XXI. Period for Whose Benefit

A period may be established for the benefit of:

the debtor;
the creditor;
both parties.

As a general rule, when a period is fixed, it is presumed to benefit both creditor and debtor, unless the tenor of the obligation or circumstances show otherwise.

If the period benefits the debtor, the creditor cannot demand payment before the due date, but the debtor may pay early.

If the period benefits the creditor, the creditor may demand early performance, but the debtor cannot force early performance.

If it benefits both, neither may compel performance before the period.

XXII. When the Debtor Loses the Benefit of the Period

The debtor may lose the right to use the period in certain cases, such as when:

after the obligation has been contracted, the debtor becomes insolvent, unless security is given;
the debtor does not furnish promised guaranties or securities;
the debtor impairs guaranties or securities after their establishment;
the debtor violates an undertaking in consideration of which the creditor agreed to the period;
the debtor attempts to abscond.

In these cases, the obligation may become immediately demandable.

XXIII. When Courts May Fix a Period

Courts may fix the duration of a period when:

the obligation does not fix a period, but from its nature and circumstances it can be inferred that a period was intended;
the duration of the period depends upon the will of the debtor.

Example: “I will pay you when my means permit me to do so.”

The court may determine a reasonable period.

XXIV. Alternative and Facultative Obligations

These obligations involve several possible prestations.

XXV. Alternative Obligations

An alternative obligation is one where several prestations are due, but the complete performance of one of them is sufficient.

Example: “I will deliver either my motorcycle, my laptop, or ₱100,000.”

The debtor is generally given the right of choice unless it has been expressly granted to the creditor.

A. Right of Choice

The right of choice may belong to:

the debtor;
the creditor;
a third person, if agreed upon.

The choice becomes effective only upon communication to the other party.

B. Limitations on Choice

The debtor cannot choose prestations that are impossible, unlawful, or could not have been the object of the obligation.

If only one prestation remains practicable, the obligation may become a simple obligation.

C. Loss of Objects Before Choice

The legal consequences depend on:

who has the right of choice;
whether the loss was due to fortuitous event;
whether the debtor was at fault;
whether all or some prestations were lost.

If all choices are lost through the debtor’s fault, the creditor may generally recover damages.

XXVI. Facultative Obligations

A facultative obligation is one where only one prestation is due, but the debtor may substitute another.

Example: “I will deliver my car, but I may instead pay ₱500,000.”

Only the principal prestation is due. The substitute is not due unless substitution is made.

Difference Between Alternative and Facultative Obligations

In an alternative obligation, several prestations are due in the alternative. In a facultative obligation, only one prestation is due, but another may be substituted.

This distinction matters in case of loss.

If the principal thing in a facultative obligation is lost through fortuitous event before substitution, the obligation may be extinguished. If the substitute is lost before substitution, the debtor may not be liable because it was not yet due.

XXVII. Joint and Solidary Obligations

These obligations involve multiple debtors, multiple creditors, or both.

XXVIII. Joint Obligations

A joint obligation is one where each debtor is liable only for a proportionate part of the debt, or each creditor is entitled only to a proportionate share of the credit.

Joint obligations are the general rule when several debtors or creditors exist, unless solidarity is expressly stated, required by law, or required by the nature of the obligation.

Example: A, B, and C jointly owe X ₱90,000. Each generally owes only ₱30,000.

The creditor cannot demand the entire ₱90,000 from A alone.

XXIX. Solidary Obligations

A solidary obligation is one where each debtor may be required to pay the entire obligation, or each creditor may demand the entire prestation.

Solidarity is never presumed. It exists only when:

the obligation expressly states it;
the law requires it;
the nature of the obligation requires it.

Common terms indicating solidarity include:

jointly and severally;
solidarily;
in solidum;
individually and collectively.

Example: A, B, and C solidarily owe X ₱90,000. X may demand the full ₱90,000 from A alone, subject to A’s right to seek reimbursement from B and C for their shares.

A. Passive Solidarity

Passive solidarity exists among several debtors. The creditor may demand full performance from any one of them.

B. Active Solidarity

Active solidarity exists among several creditors. Any one creditor may demand full performance from the debtor, subject to accounting among creditors.

C. Mixed Solidarity

Mixed solidarity exists when there are several creditors and several debtors with solidary rights and liabilities.

D. Effects of Payment by One Solidary Debtor

Payment by one solidary debtor extinguishes the obligation as to the creditor. The paying debtor may then seek reimbursement from co-debtors for their respective shares, with interest from payment if applicable.

E. Defenses Available to Solidary Debtor

A solidary debtor may raise defenses derived from:

the nature of the obligation;
defenses personal to the debtor;
defenses personal to other co-debtors, but only as to the share of those co-debtors.

XXX. Joint Indivisible Obligations

A joint indivisible obligation is one where the parties are jointly bound, but the prestation is indivisible.

Example: A, B, and C jointly undertake to deliver a specific car to X.

Because the object is indivisible, complete performance requires the cooperation of all debtors. If one debtor refuses, the obligation may be converted into one for damages.

This is different from solidarity. In joint indivisible obligations, one debtor cannot generally be compelled to perform the entire obligation alone unless the obligation or law provides solidarity.

XXXI. Divisible and Indivisible Obligations

This classification concerns whether the prestation can be partially performed.

XXXII. Divisible Obligations

An obligation is divisible when the prestation can be partially performed without changing its essence or value.

Examples:

payment of money;
delivery of goods by installments;
construction by phases;
supply of materials in batches.

Divisibility may depend on the nature of the prestation, the parties’ agreement, or the purpose of the obligation.

XXXIII. Indivisible Obligations

An obligation is indivisible when partial performance is not possible or would destroy the essence of the prestation.

Examples:

delivery of a specific car;
delivery of a particular painting;
performance of a single indivisible act;
completion of a specific structure as a whole, depending on the contract.

Obligations may be indivisible by:

nature;
law;
agreement of the parties.

Even if a thing is physically divisible, the obligation may be legally indivisible if the parties intended full performance only.

Example: A debt of money is physically divisible, but the parties may agree that payment must be made in full on a specific date.

XXXIV. Obligations with a Penal Clause

An obligation with a penal clause is one where an accessory undertaking imposes a penalty in case of breach.

Example: “If the contractor fails to finish the project by June 30, the contractor shall pay ₱10,000 per day of delay.”

The penalty may serve as:

substitute for damages and interest;
punishment for breach;
security for performance.

As a general rule, the penalty substitutes for damages and interest unless the parties agree otherwise or unless the debtor is guilty of fraud.

XXXV. Kinds of Penal Clauses

A. Subsidiary or Alternative Penalty

The penalty substitutes for the principal obligation in case of breach.

Example: If the debtor fails to deliver goods, the debtor pays the agreed penalty.

B. Joint or Cumulative Penalty

The creditor may demand both performance and penalty if this is clearly granted.

Example: The contract states that the contractor must complete the project and also pay liquidated damages for each day of delay.

C. Legal Penalty

A penalty may be imposed by law.

D. Conventional Penalty

A penalty may be agreed upon by the parties.

XXXVI. Reduction of Penalty

Courts may reduce a penalty when:

the principal obligation has been partly or irregularly complied with;
the penalty is iniquitous or unconscionable.

This is important in Philippine practice because courts may temper excessive penalties, liquidated damages, surcharges, and similar charges.

XXXVII. Civil Obligations and Natural Obligations

XXXVIII. Civil Obligations

Civil obligations are obligations enforceable by court action.

Example: A valid loan that is due and unpaid.

The creditor may sue to compel payment or recover damages.

XXXIX. Natural Obligations

Natural obligations are based on equity and natural law. They do not grant a right of action to compel performance, but once voluntarily performed, the debtor may no longer recover what has been delivered or paid.

Example: A debt that has prescribed may no longer be judicially enforced. But if the debtor voluntarily pays despite knowing that prescription has set in, the debtor generally cannot recover the payment.

Natural obligations occupy a middle ground between civil obligations and purely moral duties.

They are not enforceable by action, but voluntary fulfillment produces legal effects.

XL. Moral Obligations

Moral obligations are duties of conscience, ethics, gratitude, or social responsibility that are not legally enforceable and do not necessarily produce civil effects.

Example: A person may feel morally obliged to help a friend financially, but the friend cannot sue to compel such help unless a legal obligation exists.

XLI. Real and Personal Obligations

XLII. Real Obligations

A real obligation is an obligation to give.

Example: To deliver a parcel of land, a vehicle, goods, or money.

The term “real” in this context refers to a thing as the object of prestation.

XLIII. Personal Obligations

A personal obligation is an obligation to do or not to do.

Personal obligations are divided into:

positive personal obligations;
negative personal obligations.

A. Positive Personal Obligation

This is an obligation to do.

Example: To construct a building.

B. Negative Personal Obligation

This is an obligation not to do.

Example: Not to disclose trade secrets.

XLIV. Determinate and Generic Obligations

XLV. Determinate Obligations

A determinate obligation involves a specific thing.

Example: “Deliver my Rolex watch with serial number X.”

The debtor must deliver that exact thing. If it is lost through a fortuitous event before the debtor incurs delay and without fault, the obligation may be extinguished.

XLVI. Generic Obligations

A generic obligation involves a thing identified only by class or kind.

Example: “Deliver 1,000 kilos of sugar.”

The debtor may deliver any item within the agreed class and quality. Loss of particular items generally does not extinguish the obligation because the debtor can obtain others of the same kind.

XLVII. Limited Generic Obligations

A limited generic obligation is one where the object belongs to a particular class or source.

Example: “Deliver one of the horses in my stable.”

The obligation is not purely generic because the source is limited. If all the horses in the stable are lost without fault before delay, the obligation may be extinguished, depending on the circumstances.

XLVIII. Positive and Negative Obligations

XLIX. Positive Obligations

A positive obligation requires an act.

It may be:

to give;
to do.

Examples:

to pay money;
to deliver goods;
to repair a machine;
to render services.

L. Negative Obligations

A negative obligation requires abstention.

Example:

not to build;
not to compete;
not to disclose;
not to interfere;
not to enter.

In negative obligations, delay is generally not applicable in the same way as positive obligations because the breach occurs when the prohibited act is done.

LI. Unilateral and Bilateral Obligations

LII. Unilateral Obligations

A unilateral obligation is one where only one party is bound to perform.

Example: A simple donation, once accepted and perfected, may impose an obligation on the donor to deliver the donated thing.

Another example: A borrower is bound to repay a loan after receiving the money.

LIII. Bilateral Obligations

A bilateral obligation is one where both parties are reciprocally bound.

Example: In a sale, the seller must deliver the thing and the buyer must pay the price.

Bilateral obligations are common in contracts.

LIV. Reciprocal Obligations

Reciprocal obligations are obligations arising from the same cause, where each party is both debtor and creditor of the other.

Example: In a contract of sale:

seller is debtor as to delivery and creditor as to price;
buyer is debtor as to price and creditor as to delivery.

In reciprocal obligations, neither party generally incurs delay if the other does not comply or is not ready to comply, unless the parties agreed otherwise.

If one party substantially breaches, the injured party may seek rescission or specific performance, with damages in either case.

LV. Principal and Accessory Obligations

LVI. Principal Obligations

A principal obligation can stand by itself.

Example: A loan obligation requiring payment of ₱1,000,000.

LVII. Accessory Obligations

An accessory obligation depends on a principal obligation.

Examples:

pledge;
mortgage;
guaranty;
suretyship;
penalty clause;
interest obligation;
security agreement.

If the principal obligation is extinguished, the accessory obligation is generally extinguished as well. However, the reverse is not necessarily true: extinguishment of the accessory obligation does not automatically extinguish the principal obligation.

LVIII. Simple and Compound Obligations

LIX. Simple Obligations

A simple obligation involves only one prestation.

Example: “I will pay you ₱10,000.”

LX. Compound Obligations

A compound obligation involves two or more prestations.

Compound obligations may be:

conjunctive;
alternative;
facultative.

A. Conjunctive Obligation

A conjunctive obligation requires performance of all prestations.

Example: “I will deliver the laptop, install the software, and train your staff.”

The debtor must perform all.

B. Alternative Obligation

Several prestations are due, but one complete performance is enough.

Example: “I will give you either ₱100,000 or my motorcycle.”

C. Facultative Obligation

Only one prestation is due, but the debtor may substitute another.

Example: “I will give you my motorcycle, but I may instead pay ₱100,000.”

LXI. Individual and Collective Obligations

LXII. Individual Obligations

An individual obligation has one debtor and one creditor.

Example: A owes B ₱50,000.

LXIII. Collective Obligations

A collective obligation involves multiple debtors, multiple creditors, or both.

Collective obligations may be joint or solidary.

Example: A, B, and C owe X ₱300,000.

The legal effect depends on whether the obligation is joint or solidary.

LXIV. Obligations According to Performance

LXV. Instantaneous Obligations

An instantaneous obligation is performed at one time.

Example: Delivery of a specific watch.

LXVI. Periodic Obligations

A periodic obligation requires performance at intervals.

Example: Monthly rent payments.

LXVII. Continuing Obligations

A continuing obligation requires sustained conduct over time.

Example: Maintaining confidentiality for five years.

LXVIII. Successive Obligations

A successive obligation requires a series of performances.

Example: Supplying 1,000 units every month for one year.

LXIX. Obligations According to Sanction

LXX. Enforceable Obligations

These are obligations that may be enforced in court.

Example: A valid promissory note that has matured.

LXXI. Void Obligations

A void obligation produces no legal effect and cannot be ratified.

Example: An obligation with an illegal cause.

LXXII. Voidable Obligations

A voidable obligation is valid until annulled.

Examples include obligations arising from contracts where consent was vitiated by mistake, violence, intimidation, undue influence, or fraud, or where a party was incapable of giving consent.

LXXIII. Unenforceable Obligations

An unenforceable obligation cannot be sued upon unless ratified.

Examples may include certain contracts entered into without authority, contracts that fail to comply with the Statute of Frauds, or contracts where both parties are incapable of giving consent.

LXXIV. Rescissible Obligations

A rescissible obligation is valid but may be rescinded because of economic prejudice or lesion in cases provided by law.

Example: Certain contracts entered into by guardians on behalf of wards when the ward suffers legally significant lesion.

LXXV. Obligations According to Cause

LXXVI. Onerous Obligations

An onerous obligation imposes a burden on both parties, usually involving valuable consideration.

Example: Sale, lease, employment, construction contract.

LXXVII. Gratuitous Obligations

A gratuitous obligation is based on liberality.

Example: Donation.

LXXVIII. Remuneratory Obligations

A remuneratory obligation is given to reward a past service or benefit that does not constitute a demandable debt.

Example: A person gives property to another in recognition of past assistance.

LXXIX. Obligations According to Object

LXXX. Obligations Involving Things

These include obligations to deliver determinate or generic things.

Example: delivery of land, vehicle, equipment, inventory, money, or documents.

LXXXI. Obligations Involving Services

These include obligations to perform acts.

Example: construction, repair, consulting, teaching, transport, medical service, legal service.

LXXXII. Obligations Involving Forbearance

These include obligations to refrain from acts.

Example: confidentiality, non-disparagement, non-use, non-interference, non-compete, non-solicitation.

LXXXIII. Obligations According to Demandability

LXXXIV. Immediately Demandable Obligations

These are obligations that may be demanded at once.

Examples:

pure obligations;
obligations subject to a resolutory condition;
obligations with an expired period.

LXXXV. Not Yet Demandable Obligations

These are obligations whose demandability has not yet arrived.

Examples:

obligations subject to a suspensive condition not yet fulfilled;
obligations with a suspensive period not yet arrived.

LXXXVI. Extinguished Obligations

These are obligations that no longer exist due to a mode of extinguishment.

Examples:

payment or performance;
loss of the thing due;
condonation;
confusion or merger;
compensation;
novation;
annulment;
rescission;
fulfillment of resolutory condition;
prescription.

LXXXVII. Obligations According to Breach

LXXXVIII. Obligations Breached by Delay

Delay, or mora, occurs when the debtor fails to perform on time despite demand, when demand is required.

Kinds of delay include:

mora solvendi – delay by the debtor;
mora accipiendi – delay by the creditor;
compensatio morae – delay in reciprocal obligations.

In many obligations, delay begins only after judicial or extrajudicial demand. However, demand may not be necessary when:

the obligation or law expressly so declares;
time is of the essence;
demand would be useless;
the debtor has rendered performance impossible;
in reciprocal obligations, one party performs or is ready to perform and the other does not.

LXXXIX. Obligations Breached by Fraud

Fraud, or dolo, involves deliberate evasion of normal fulfillment of an obligation.

Responsibility arising from fraud is demandable in all obligations. Waiver of future fraud is void.

Example: A seller intentionally conceals that the object sold has been destroyed.

XC. Obligations Breached by Negligence

Negligence, or culpa, is the omission of the diligence required by the nature of the obligation and corresponding to the circumstances of persons, time, and place.

If the law or contract does not state the required diligence, the standard is generally the diligence of a good father of a family.

XCI. Obligations Breached by Contravention of Terms

This occurs when the debtor violates the tenor or terms of the obligation.

Example: A supplier delivers goods of a different quality from that agreed upon.

XCII. Obligations According to Liability for Fortuitous Events

XCIII. General Rule

No person is generally responsible for events that could not be foreseen, or which, though foreseen, were inevitable.

These are fortuitous events.

Examples:

natural disasters;
war;
sudden government prohibitions;
extraordinary accidents;
events beyond human control.

However, this rule has exceptions.

XCIV. Exceptions: Liability Despite Fortuitous Event

A debtor may still be liable for a fortuitous event when:

the law so provides;
the contract so provides;
the nature of the obligation requires assumption of risk;
the debtor is already in delay;
the debtor has promised to deliver the same thing to two or more persons with different interests;
the fortuitous event is partly caused by the debtor’s fault or negligence.

Example: If a debtor is already in delay in delivering a specific car and the car is later destroyed by a flood, the debtor may still be liable.

XCV. Obligations According to Standard of Care

XCVI. Ordinary Diligence

The usual standard is the diligence of a good father of a family.

This means reasonable care expected of a prudent person under similar circumstances.

XCVII. Extraordinary Diligence

Some obligations require extraordinary diligence.

Examples include obligations of common carriers, where the law imposes a high degree of care due to public policy.

XCVIII. Contractual Standard of Diligence

Parties may agree on a standard of care, provided it is not contrary to law, morals, good customs, public order, or public policy.

Example: A warehouse contract may require specific security and preservation measures.

XCIX. Obligations According to Remedies

C. Obligations Enforceable by Specific Performance

Some obligations may be enforced by compelling performance.

Example: Delivery of a specific thing.

CI. Obligations Enforceable by Substitute Performance

If the debtor fails to do an act, the creditor may have it performed by another at the debtor’s expense, when the act is not purely personal.

Example: A contractor fails to repair a fence; the owner may have another contractor do it and charge the cost to the original contractor, subject to proper legal process.

CII. Obligations Enforceable by Undoing

If the debtor does what has been forbidden, the act may be undone at the debtor’s expense when possible.

Example: Removal of a structure built in violation of an obligation not to build.

CIII. Obligations Enforceable by Damages

When specific performance is impossible, impractical, or legally improper, damages may be awarded.

Examples:

breach of personal service contract;
loss of determinate thing through debtor’s fault;
delay causing loss;
negligent performance;
fraudulent breach.

CIV. Obligations According to Extinguishment

CV. Obligations Extinguished by Payment or Performance

Payment means not only delivery of money but performance of the obligation.

An obligation is extinguished when the prestation is completely performed.

CVI. Obligations Extinguished by Loss of the Thing Due

If a determinate thing is lost without the debtor’s fault and before delay, the obligation may be extinguished.

This generally does not apply to generic obligations.

CVII. Obligations Extinguished by Condonation or Remission

The creditor may gratuitously forgive the debt, subject to rules on donations and acceptance.

CVIII. Obligations Extinguished by Confusion or Merger

Confusion occurs when the characters of creditor and debtor are merged in the same person.

Example: A debtor inherits the credit against himself.

CIX. Obligations Extinguished by Compensation

Compensation occurs when two persons are creditors and debtors of each other, and their debts are of the same kind and quality, due, liquidated, and demandable.

Example: A owes B ₱100,000, while B owes A ₱70,000. Compensation may extinguish the obligations up to ₱70,000.

CX. Obligations Extinguished by Novation

Novation extinguishes an obligation by substituting or changing:

the object or principal conditions;
the debtor;
the creditor.

Novation is never presumed. It must be clear.

CXI. Obligations Extinguished by Annulment, Rescission, Fulfillment of Resolutory Condition, or Prescription

Obligations may also be extinguished by:

annulment of voidable contracts;
rescission in cases allowed by law;
fulfillment of resolutory conditions;
prescription or lapse of time.

CXII. Obligations According to Proof

CXIII. Written Obligations

Written obligations are embodied in documents such as contracts, promissory notes, deeds, letters, invoices, receipts, and electronic records.

They are generally easier to prove.

CXIV. Oral Obligations

Oral obligations may be valid, except when the law requires a writing for enforceability, validity, or evidentiary purposes.

Certain agreements may fall under the Statute of Frauds and may be unenforceable unless in writing or ratified.

CXV. Implied Obligations

Implied obligations arise from conduct, law, usage, equity, or the nature of the transaction.

Example: A restaurant customer who orders food is obliged to pay, even without signing a written contract.

CXVI. Obligations in Common Legal Transactions

CXVII. Sale

In a sale:

the seller is obliged to deliver and warrant the thing sold;
the buyer is obliged to pay the price.

The obligations are reciprocal.

CXVIII. Lease

In lease:

the lessor must allow use or enjoyment of the property;
the lessee must pay rent and use the property properly.

There may be continuing and periodic obligations.

CXIX. Loan

In a loan:

the borrower must return money or equivalent consumable things;
if interest is agreed upon, interest must comply with legal requirements.

CXX. Employment

In employment:

the employee must render service;
the employer must pay wages and comply with labor standards.

Employment obligations are affected by labor law and public policy.

CXXI. Construction

In construction:

the contractor must complete the work according to plans and specifications;
the owner must pay the contract price.

There may be obligations to do, obligations with a period, penal clauses, warranties, and damages for delay.

CXXII. Insurance

In insurance:

the insured must pay premiums and disclose material facts;
the insurer must pay covered losses according to policy terms.

CXXIII. Agency

In agency:

the agent must act within authority and account to the principal;
the principal must comply with obligations arising from authorized acts.

CXXIV. Partnership

In partnership:

partners contribute money, property, or industry;
partners share profits and losses according to law or agreement.

CXXV. Practical Importance of Classifying Obligations

Classifying an obligation is not academic. It affects legal rights and remedies.

For example:

If the obligation is pure, it is demandable at once.
If conditional, demandability depends on fulfillment of the condition.
If with a period, the creditor must wait until the period arrives.
If determinate, loss of the specific thing may extinguish liability.
If generic, loss generally does not extinguish liability.
If alternative, choice matters.
If facultative, only the principal prestation is due before substitution.
If joint, each debtor owes only a share.
If solidary, one debtor may be liable for all.
If divisible, partial performance may be possible.
If indivisible, complete performance may be required.
If with penal clause, the agreed penalty may substitute for damages.
If natural, court enforcement may not be available.

The classification determines the available remedies, defenses, timing of demand, measure of damages, and effect of impossibility.

CXXVI. Common Mistakes in Understanding Obligations

1. Confusing a Condition with a Period

A condition is uncertain. A period is certain.

“If I pass the exam” is a condition. “On December 31” is a period.

2. Assuming All Multiple-Debtor Obligations Are Solidary

The general rule is joint liability. Solidarity must be clearly provided by law, contract, or nature of the obligation.

3. Thinking a Generic Obligation Is Extinguished by Loss

Generic things generally do not perish legally because the debtor can provide another item of the same kind.

4. Treating a Facultative Obligation as Alternative

In a facultative obligation, only one prestation is due. In an alternative obligation, several prestations are due, but one performance completes the obligation.

5. Assuming a Penalty Is Always Added to Damages

A penalty usually substitutes for damages and interest unless otherwise agreed or unless special circumstances exist.

6. Thinking Moral Duties Are Always Legal Obligations

Only juridical obligations are enforceable. Moral duties may not be demandable in court.

7. Believing Demand Is Always Necessary for Delay

Demand is often required, but not always. The law recognizes exceptions.

8. Assuming Written Form Is Always Required

Many obligations may be valid even if oral, though proof and enforceability issues may arise.

CXXVII. Illustrative Examples

Example 1: Pure Obligation

“I promise to pay you ₱20,000.”

This is demandable at once if no period or condition is stated.

Example 2: Suspensive Condition

“I will pay you ₱20,000 if my visa is approved.”

The obligation becomes demandable only if the visa is approved.

Example 3: Resolutory Condition

“You may use my car until my brother returns from abroad.”

The right ends when the brother returns.

Example 4: Obligation with a Period

“I will pay you ₱20,000 on June 30.”

The obligation exists but is demandable only on June 30.

Example 5: Alternative Obligation

“I will give you my laptop or my tablet.”

Either prestation may satisfy the obligation, depending on who has the right of choice.

Example 6: Facultative Obligation

“I will give you my laptop, but I may instead give you ₱30,000.”

Only the laptop is due before substitution.

Example 7: Joint Obligation

“A, B, and C owe X ₱90,000 jointly.”

Each owes ₱30,000.

Example 8: Solidary Obligation

“A, B, and C bind themselves jointly and severally to pay X ₱90,000.”

X may collect the full amount from any one of them.

Example 9: Divisible Obligation

“Deliver 100 sacks of rice in four equal monthly installments.”

The obligation may be performed by parts.

Example 10: Indivisible Obligation

“Deliver the original painting of a named artist.”

Partial delivery is impossible.

Example 11: Penal Clause

“For every day of delay, the contractor shall pay ₱5,000.”

The penalty may apply in case of delay, subject to possible reduction if unconscionable.

CXXVIII. Conclusion

The law on obligations under the Civil Code of the Philippines provides the foundation for private legal relations. Obligations may arise from law, contracts, quasi-contracts, crimes, and quasi-delicts. They may require a person to give, to do, or not to do. They may be pure, conditional, with a period, alternative, facultative, joint, solidary, divisible, indivisible, principal, accessory, civil, natural, or subject to a penal clause.

Each classification has practical legal consequences. It determines when the obligation becomes demandable, who may enforce it, who may be held liable, whether partial performance is allowed, what happens in case of loss, whether damages may be recovered, and what defenses may be raised.

The central principle remains constant: an obligation is a legal bond. Once validly created, it must be performed according to its terms, in good faith, and in accordance with law. Where performance fails, Philippine law supplies remedies to protect the injured party while also recognizing defenses, exceptions, and equitable limitations.