A supplier usually cannot change the price after delivery if you and the supplier already agreed on the goods and the price. Under Philippine law, a sale is binding once there is a meeting of minds on the item and the price. Delivery and receipt of the goods usually make the agreed terms even clearer. The difficult part is proving what the agreed price was, whether there was a valid price-adjustment clause, and whether the buyer accepted the new price later.

In real life, this issue often happens when a supplier sends a revised invoice after delivery, adds “updated pricing” due to exchange rate or fuel costs, claims the quotation was only an estimate, or refuses to release the official invoice unless the buyer pays more. The right answer depends on the documents, messages, delivery receipts, purchase order, invoice, and the conduct of both parties.

The General Rule: The Agreed Price Controls

In the Philippines, a contract is a meeting of minds. The Civil Code says a contract exists when one party binds himself to give something or render service, and the other accepts the obligation. Once a contract is perfected, it has the force of law between the parties and must be complied with in good faith. (Lawphil)

For a sale of goods, the Civil Code is even more direct:

A sale requires a determinate thing and a price certain in money or its equivalent.
A contract of sale is perfected when there is a meeting of minds on the thing and the price.
From that moment, both parties may demand performance. (Lawphil)

This means that if the supplier quoted ₱100,000, you accepted, the goods were delivered, and there was no valid price-adjustment clause, the supplier generally cannot later say: “The price is now ₱120,000 because our costs increased.”

A revised invoice alone is not automatically a new contract. It is usually just the supplier’s unilateral document unless the buyer accepted the change.

Why a Supplier Cannot Usually Change the Price Unilaterally

Philippine contract law follows the principle of mutuality of contracts. Article 1308 of the Civil Code says the contract must bind both parties, and its validity or compliance cannot be left to the will of only one party. (Lawphil)

The Supreme Court has repeatedly applied this principle. In Villa Crista Monte Realty & Development Corporation v. Equitable PCI Bank, the Court explained that contract changes must still have the consent of the contracting parties, especially when the change affects an important or material part of the agreement. (Supreme Court E-Library)

Price is a material part of a sale. A supplier cannot normally reserve to itself the uncontrolled power to change the price after the buyer has already ordered and received the goods. If the price can be changed by the supplier alone, the buyer is no longer truly bound by an agreed contract; the buyer is being made subject to whatever amount the supplier later chooses.

When a Supplier May Validly Change the Price After Delivery

There are situations where a post-delivery price change may be valid. The key question is whether the change is based on the contract, the law, or the buyer’s later agreement.

Situation	Is the price change likely valid?	Practical example
The contract has a clear price-escalation clause	Possibly yes	“Final price subject to published steel index on delivery date.”
The buyer agreed to the revised price after delivery	Yes, if consent is clear	Buyer signs revised invoice or pays the increase without protest.
The original price was only an estimate	Depends on proof	Repair or custom fabrication where final quantity was unknown.
The delivered quantity or specifications changed	Possibly yes	Buyer ordered 100 units but accepted 130 units.
The original price was based on a third-party formula	Possibly yes	Price tied to exchange rate, commodity index, or manufacturer price list.
The supplier simply changed its mind	Usually no	Supplier says costs increased but contract had no adjustment clause.
The supplier made an internal costing mistake	Usually no	Supplier’s staff quoted the wrong margin but buyer accepted in good faith.
The displayed retail price was lower	Usually no for consumer retail sale	Store price tag says ₱999 but cashier charges ₱1,199.

1. There is a clear price-adjustment clause

A supplier may rely on a price-adjustment clause if it was part of the agreement before or at the time of the sale.

Common examples:

“Price subject to final supplier/manufacturer price on delivery date.”
“Prices may change based on foreign exchange rate at time of importation.”
“Final billing based on actual weight delivered.”
“Quotation valid for seven days only.”
“Fuel surcharge applies if delivery cost increases beyond agreed rate.”

But the clause must be clear enough to determine the price objectively. Under Article 1469 of the Civil Code, the price may be considered certain if it is fixed with reference to another certain thing, or if determination is left to a special person or persons. Article 1473 also states that fixing the price can never be left to the discretion of one contracting party alone, although the sale is perfected if the other party accepts the price fixed. (Lawphil)

So, “Supplier may adjust the price as it deems necessary” is much weaker than “Final price shall be based on the Bangko Sentral ng Pilipinas USD-PHP exchange rate on the delivery date plus 3% handling charge.”

2. The buyer accepted the new price

Even if the supplier could not originally impose the increase, the buyer may later agree to it.

Acceptance may be shown by:

signing a revised quotation, purchase order, or invoice;
sending an email or message saying “approved” or “okay”;
paying the increased amount without objection;
continuing to order goods under the revised pricing; or
accepting additional deliveries after being clearly notified of the new price.

But acceptance should be clear. Silence alone is risky to interpret. A buyer who receives a revised invoice and immediately objects in writing is in a much stronger position than a buyer who ignores it for months and continues transacting as usual.

3. The quantity, weight, or specifications changed

A supplier may charge more if the buyer received more than what was originally priced.

Examples:

The purchase order was for 50 sacks, but the buyer accepted 70 sacks.
The quote was for standard materials, but the buyer requested premium-grade materials.
The price was per kilo, cubic meter, board foot, or liter, and the final delivered quantity was higher.
The buyer requested rush delivery, special packaging, cold-chain transport, or additional handling.

In these cases, the issue is not really a unilateral price increase. It is a dispute over the correct computation under the actual order.

4. The original “price” was only an estimate

Some transactions are naturally estimate-based, especially repairs, construction materials, made-to-order items, importation, and services with variable labor or parts.

But suppliers should not abuse the word “estimate.” A document labeled “quotation” may still become binding if:

the item is clearly identified;
the price is fixed;
the buyer accepts within the quotation validity period;
the supplier confirms the order; and
the supplier delivers.

In ordinary commercial dealings, a quotation accepted through a purchase order often becomes part of the contract.

5. The price was never agreed, but the buyer kept the goods

If no price was fixed and the buyer still received and used the goods, the buyer may still have to pay a reasonable price. Article 1474 of the Civil Code provides that if the price cannot be determined but the thing or part of it has been delivered and appropriated by the buyer, the buyer must pay a reasonable price. (Lawphil)

This usually applies when there was no definite price agreement, not when there was a definite price that the supplier later wants to increase.

Consumer Transactions: Price Tags and Retail Overcharging

If the buyer is a consumer buying goods for personal, family, household, or agricultural purposes, the Consumer Act of the Philippines, Republic Act No. 7394, may apply. The law defines consumer products and services as those primarily for personal, family, household, or agricultural purposes, and treats consumer transactions broadly. (Supreme Court E-Library)

For retail sales, Article 81 of the Consumer Act makes it unlawful to offer a consumer product for retail sale without an appropriate price tag, label, or marking, and states that the product shall not be sold at a price higher than that stated. Price tags must also be clearly written in pesos and centavos, and there should be no erasures or alterations of price tags, labels, or markings. (Supreme Court E-Library)

This matters when a store, online seller, or retail supplier tries to charge a higher price after the buyer has relied on the displayed price.

Examples:

A grocery shelf tag says ₱150, but the cashier charges ₱180.
An appliance store tag says “₱24,999 cash price,” but after delivery the store asks for ₱27,500.
An online seller confirms a price, delivers the item, then asks for extra payment before issuing the invoice.

For consumer complaints involving price tags, deceptive sales acts, or unfair trade practices, the Department of Trade and Industry’s Consumer CARe system is the usual administrative route for filing a complaint online. (DTI Consumer Care System)

Business-to-Business Transactions: What Usually Matters Most

For B2B transactions, the Consumer Act may not always apply because the purchase may not be for personal, family, household, or agricultural use. The Civil Code, the parties’ contract, and commercial documents usually become the main basis.

In supplier disputes, the most important documents are usually:

Document	Why it matters
Quotation or proposal	Shows the offered price, validity period, inclusions, taxes, freight, and conditions.
Purchase order	Shows the buyer’s acceptance and requested quantity/specifications.
Order confirmation	Shows the supplier accepted the order.
Contract or terms and conditions	May contain price escalation, cancellation, tax, freight, and dispute clauses.
Delivery receipt	Shows what was actually delivered and received.
Invoice or billing invoice	Shows what the supplier billed and when.
Emails, Viber, Messenger, WhatsApp, SMS	May prove agreement, objection, or later acceptance.
Proof of payment	Shows payment of admitted amount or acceptance of revised amount.
Accounting records	Useful for businesses claiming input VAT, deductions, or payables.

Since electronic messages and documents are now common, remember that the Electronic Commerce Act, Republic Act No. 8792, recognizes electronic documents and allows offer, acceptance, and contract elements to be expressed and proved through electronic data messages or electronic documents. (Supreme Court E-Library)

What to Do If a Supplier Demands a Higher Price After Delivery

Do not rely only on phone calls. Put your position in writing and preserve the evidence.

1. Review the original pricing documents

Check the:

quotation validity period;
purchase order;
supplier’s terms and conditions;
delivery receipt;
invoice or billing invoice;
emails and messages before delivery;
any “subject to change” wording;
VAT, delivery fee, fuel surcharge, customs duties, or handling charge provisions.

Focus on whether the price was fixed or formula-based.

2. Confirm what was actually delivered

Compare the delivery receipt against the purchase order.

Check:

quantity;
unit price;
brand/model/specification;
delivery date;
delivery address;
taxes and freight;
shortages, substitutions, or excess deliveries.

If the supplier delivered more than ordered, separate the undisputed items from the disputed ones.

3. Object in writing immediately

Send a short written objection by email or other traceable message.

A practical format:

We acknowledge receipt of your revised invoice dated . We dispute the increased price because our agreed price under your quotation dated ____ and our purchase order dated ____ was ₱. We accepted delivery based on that agreed price. Please issue a corrected invoice for the agreed amount. This is without prejudice to our rights and remedies.

Avoid emotional language. The goal is to create a clear record that you did not accept the revised price.

4. Pay the undisputed amount, if appropriate

If you genuinely owe the original agreed price, paying or offering to pay that amount may help show good faith.

If the supplier refuses to accept the agreed amount or refuses to issue a proper invoice or receipt, note that Article 1256 of the Civil Code allows consignation in proper cases when a creditor unjustly refuses tender of payment, although consignation is a formal court process and must strictly comply with legal requirements. (Lawphil)

5. Ask for the legal and contractual basis of the increase

Request the supplier to identify the exact clause, document, or law supporting the added charge.

Ask for:

copy of the signed terms and conditions;
computation of the revised price;
basis for exchange rate or commodity adjustment;
proof of additional quantity or upgraded specification;
breakdown of freight, taxes, customs duties, or surcharges.

A supplier with a valid basis should be able to explain the computation clearly.

6. Preserve electronic evidence properly

Keep the original thread. Do not rely only on cropped screenshots.

Save:

full email headers if possible;
PDFs of email chains;
screenshots showing sender, date, time, and full context;
delivery photos;
signed delivery receipts;
proof of bank transfer;
call logs;
company chat approvals.

The Supreme Court Rules on Electronic Evidence state that electronic documents are admissible if they comply with the Rules of Court on admissibility. (Lawphil)

Remedies If the Supplier Insists

The best remedy depends on the amount, the parties, and the nature of the transaction.

Situation	Possible route	Notes
Consumer retail overcharging	DTI consumer complaint	Useful for price tag, deceptive sales, and consumer redress issues.
Both parties are natural persons in the same city/municipality	Barangay conciliation first, if covered	Often required before court filing.
Money claim up to ₱1,000,000	Small claims case	Faster, simplified, first-level court procedure.
Money claim above ₱1,000,000 but up to ₱2,000,000	First-level court, usually under expedited/summary rules depending on case	RA 11576 expanded first-level court jurisdiction.
Money claim above ₱2,000,000	Regional Trial Court	Ordinary civil action may be needed.
Contract has arbitration clause	Arbitration or agreed dispute process	Check the contract before filing elsewhere.

Barangay conciliation

If the dispute is between natural persons actually residing in the same city or municipality and no exception applies, barangay conciliation under the Local Government Code may be a pre-condition before filing in court. Supreme Court guidance and RA 7160 treat covered barangay conciliation as a required prior step for covered disputes. (Lawphil)

This often does not apply the same way to corporations, partnerships, or parties residing in different cities or municipalities, so check the parties carefully.

Small claims

If the issue is a money claim arising from sale of personal property and the amount does not exceed ₱1,000,000, small claims may be available in the first-level courts. The Supreme Court’s Rules on Expedited Procedures increased the small claims threshold to ₱1,000,000 and cover money owed under sale of personal property. The rules also provide for a simplified process, one hearing day, and judgment within 24 hours from termination of hearing. (Supreme Court of the Philippines)

Small claims is commonly used for unpaid invoices, unpaid goods, and straightforward collection disputes. It can be used by a supplier trying to collect the agreed price, or by a buyer seeking refund of an overpayment, depending on the facts.

Larger civil claims

Republic Act No. 11576 expanded the jurisdiction of first-level courts to civil actions where the demand does not exceed ₱2,000,000, exclusive of interest, damages, attorney’s fees, litigation expenses, and costs. Claims above that usually fall under the Regional Trial Court. (Supreme Court E-Library)

Common Scenarios

The supplier delivered first, then sent a higher invoice

If there was already a fixed agreed price, the buyer can dispute the increase and request a corrected invoice. The supplier must point to a valid contractual or legal basis for the higher amount.

The quotation said “prices subject to change without prior notice”

This clause helps the supplier only up to a point. If the buyer already accepted the quotation and the supplier confirmed and delivered the goods, the supplier may still need to show that the clause was part of the agreement and that the buyer accepted the price change. A clause that leaves the final price entirely to the supplier’s uncontrolled discretion may be vulnerable under the mutuality principle.

The supplier says the staff made a pricing mistake

A supplier’s internal mistake does not automatically bind the buyer to a higher price. But if the price was obviously impossible or absurd, or the buyer knew there was a mistake and took advantage of it, the supplier may have arguments based on mistake, bad faith, or absence of true consent. Ordinary discounting or a low margin is not the same as an obvious mistake.

The buyer accepted the goods but did not sign the revised invoice

Acceptance of goods is not always acceptance of a higher price. If the agreed price was already fixed, receiving the goods usually supports completion of the original sale. But if the buyer later uses the goods, stays silent despite clear notice of a revised price, and continues ordering under the new price, the supplier may argue implied acceptance.

The supplier refuses to issue an invoice unless the buyer pays the increase

For business buyers, this creates both contract and tax documentation problems. Since the BIR’s Ease of Paying Taxes framework under RA 11976 treats invoicing as part of current tax compliance, businesses should keep proper invoices and supporting documents for sales and purchases. (Bureau of Internal Revenue)

The buyer should document the refusal, request the invoice for the agreed price in writing, and preserve proof of tender or payment of the undisputed amount.

The buyer is abroad or a foreigner dealing with a Philippine supplier

A foreign buyer or Filipino abroad should make sure the authority of any local representative is documented. If a representative in the Philippines will sign settlement papers, receive refunds, or appear before offices, a Special Power of Attorney may be required. Philippine consulates commonly notarize private documents such as special powers of attorney for use in the Philippines, and apostille rules may apply depending on where the document is executed. (Philippine Embassy)

How to Prevent This Problem in Future Supplier Contracts

A short, clear purchase order can prevent a large dispute later. Include:

Exact unit price and total price
- State whether VAT is included or excluded.
- State whether delivery, customs duties, installation, or handling are included.
Quotation validity
- Example: “This purchase order accepts Supplier’s quotation dated ____ within its validity period.”
No unilateral price changes
- Example: “No price increase shall be valid unless approved in writing by Buyer before delivery.”
Change order process
- Example: “Any change in quantity, specification, delivery cost, or price must be covered by a written change order signed or approved by both parties.”
Delivery acceptance wording
- Example: “Receipt of goods confirms quantity received only and does not waive Buyer’s right to dispute price, quality, or billing.”
Invoice requirements
- Require the invoice to match the purchase order unless there is an approved change order.
Dispute venue or process
- State whether disputes go to negotiation, mediation, arbitration, or Philippine courts.

Frequently Asked Questions

Can a supplier increase the price after delivery in the Philippines?

Usually, no. If the buyer and supplier already agreed on the goods and the price, the supplier cannot unilaterally increase the price after delivery. A valid increase generally requires a contract clause, an objective pricing formula, a change in quantity/specifications, or the buyer’s later consent.

What if the supplier sends a revised invoice after I received the goods?

A revised invoice is not automatically binding. Check whether the original contract allowed the adjustment. If not, dispute the revised invoice in writing and ask for the basis of the increase.

Do I still have to pay if I already used the goods?

You generally have to pay the agreed price. If no price was agreed and you kept or used the goods, you may have to pay a reasonable price. But using the goods does not automatically mean you accepted a higher price if there was already a fixed agreed price and you promptly objected.

Is a quotation legally binding in the Philippines?

A quotation by itself is usually an offer or proposal. It can become binding when the buyer accepts it and the supplier confirms, performs, or delivers under it. The exact effect depends on the wording, validity period, acceptance, and conduct of the parties.

What if the quotation says “price subject to change”?

That wording may allow changes before acceptance or before a firm order, but it does not always allow the supplier to change the price after the sale has been perfected and delivery made. The clause must be read with the full contract and the parties’ conduct.

Can a store charge more than the displayed price tag?

For consumer retail goods, the Consumer Act says products shall not be sold at a price higher than the stated price tag, label, or marking. This is different from many B2B supplier disputes, where the Civil Code and contract documents are usually the main basis.

Can I file a DTI complaint for post-delivery price increase?

You may consider a DTI complaint if the transaction is a consumer transaction, such as retail overcharging, misleading pricing, or unfair sales practices. For purely commercial B2B disputes, the remedy is usually contractual negotiation, arbitration if agreed, or a civil money claim in court.

Can the supplier sue me if I refuse to pay the increased amount?

The supplier can sue if it believes money is owed, but it must prove the basis of the claimed amount. Under the Civil Code, a seller may maintain an action for the price when the buyer wrongfully refuses to pay according to the terms of the sale. The key phrase is “according to the terms” of the contract. (Lawphil)

Should I pay the original amount while disputing the increase?

Often, paying or offering to pay the undisputed original amount helps show good faith. Make it clear in writing that the payment is for the agreed price and not an acceptance of the increased billing.

What evidence is most important in a supplier price dispute?

The strongest evidence is usually the quotation, purchase order, order confirmation, delivery receipt, invoice, proof of payment, and written messages showing the agreed price. Preserve full email threads and chat histories, not just cropped screenshots.

Key Takeaways

A supplier generally cannot change the price after delivery if there was already an agreed price.
Under the Civil Code, a sale is perfected when there is a meeting of minds on the item and the price.
A unilateral revised invoice does not automatically bind the buyer.
A price increase may be valid if the contract has a clear adjustment clause, the buyer agreed, the quantity/specifications changed, or the original price was never fixed.
For consumer retail sales, goods generally cannot be sold above the displayed price tag.
Object to the increased price in writing as soon as possible.
Preserve quotations, purchase orders, delivery receipts, invoices, payment records, and electronic messages.
Small claims may be available for sale-of-goods money claims up to ₱1,000,000.
Clear purchase orders and written change-order rules are the best protection against post-delivery price disputes.