Short answer: Yes, you usually can cancel—but how you cancel, what you’ll get back, and what you may forfeit depend on your contract type, your seller’s conduct, and specific Philippine statutes (notably the Civil Code and the “Maceda Law” for residential installment sales). Below is a practical, doctrine-grounded guide.

1) First, identify what kind of transaction you actually have

Before talking about “cancellation,” pin down the legal frame:

Contract to Sell vs. Deed of Absolute Sale (DOAS).
- In many developer purchases, you sign a Reservation Agreement then a Contract to Sell (CTS). Title remains with the seller until you fully pay and sign the DOAS for transfer/registration.
- If no DOAS yet, ownership likely hasn’t transferred; you’re still in the “executory” phase.
Installment plan or lump sum?
- If installments for a residential unit/lot, R.A. 6552 (the “Maceda Law”) likely applies.
- If not an installment sale (e.g., a near-cash deal or commercial property), Maceda may not apply, and you fall back mainly on the Civil Code + your written contract.
Developer sale vs. private seller.
- PD 957 (Subdivision and Condominium Buyers’ Decree) protects buyers mainly against developer noncompliance (e.g., failure to develop), which may trigger cancellation/refund rights.
- For private resales, PD 957 usually doesn’t govern; your contract and the Civil Code do.
Is there a written contract?
- Sales of real property must be in writing under the Statute of Frauds (Civil Code Art. 1403) to be enforceable in court while executory.
- Partial performance (substantial payments, possession, etc.) can remove it from the Statute, but in practice you’ll still rely on the written CTS/terms for cancellation, penalties, and refunds.

2) Three main legal pathways to “cancellation”

A) Buyer-initiated cancellation under the contract (no seller breach)

Most CTS forms let the buyer withdraw subject to forfeiture/penalties. Common outcomes:

Reservation fee forfeited; sometimes a portion of monthly installments forfeited as liquidated damages.
Courts may reduce unconscionable penalties (Civil Code Art. 1229), but that takes litigation/negotiation.

B) Buyer cancellation with statutory protection (Maceda Law) — for residential installment sales

If you purchased a residential lot/house/condo on installment from an owner/developer and you’ve paid at least two years of installments, you’re entitled, upon cancellation, to:

A cash surrender value of at least 50% of total payments, plus an additional 5% per year after the second year, capped at 90%.
Cancellation must be by notarial notice, and you must be given at least 30-day grace to update arrears before cancellation can take effect. If you’ve paid less than two years, you’re generally entitled to a grace period (no more than once every five years) to pay without immediate cancellation; exact terms vary under the statute.

Paying “70%” does not automatically equal “two years” under Maceda—the metric is years of installments paid, not just the percentage of price. But in practice, a buyer at 70% often meets the two-year threshold (confirm your timeline).

C) Resolution/Rescission because of seller breach (Civil Code Art. 1191; PD 957 in developer failures)

If the seller is in breach (e.g., unjustified delays in completion/turnover, material deviations, concealed defects):

You may cancel (resolve) the contract and claim damages under Art. 1191.
Under PD 957, serious developer violations (e.g., failure to develop per approved plans) can justify rescission with restitution, often via the housing regulator.
This route aims for fuller refunds (sometimes interest/damages), but you must prove breach.

3) What happens to the 70% you already paid?

It hinges on the framework above:

Under Maceda (installment, residential, 2+ years paid):
- Refund = ≥50% of total payments +5% per year beyond two years (max 90%).
- Example: Price ₱5,000,000; total paid ₱3,500,000 (70%). If you paid 4 years of installments:
  - Base 50% of ₱3,500,000 = ₱1,750,000
  - Extra 5% × (4−2) = 10% of ₱3,500,000 = ₱350,000
  - Cash surrender value: ₱2,100,000 (60%), subject to cap ≤90% (not binding here).
Contract-based withdrawal (no Maceda coverage):
- Expect forfeiture of reservation and possibly a contract penalty on installments (e.g., 10–20%).
- Courts can moderate penalties if clearly excessive. Negotiation often improves outcomes.
Seller breach (Art. 1191 / PD 957):
- You can seek cancellation + full or near-full refund and damages. Success depends on evidence of breach.

4) Tax and title timing (why the missing Deed matters)

No DOAS signed usually means no transfer yet; the title stays with seller.
Capital Gains Tax (CGT) and Documentary Stamp Tax (DST) tied to the transfer are normally not triggered if the sale is not consummated.
If you cancel before DOAS/registration, you avoid post-transfer unwind (which is messier and costlier).

5) Practical playbook: how to cancel cleanly

Audit your paperwork.
- Reservation Agreement, CTS, payment ledger, official receipts, turnover schedule, project permits/marketing, correspondence.
- Note clauses on cancellation, forfeiture, liquidated damages, default, and assignment of rights.
Check which law applies.
- Residential + installment + 2+ years → Maceda rights likely.
- Developer failure → consider PD 957 remedies.
- Otherwise → Civil Code + contract terms.
Compute scenarios.
- (a) Maceda refund, (b) contract penalty/forfeiture, (c) seller-breach damages.
- Keep a simple table of “Best Case / Likely / Worst Case.”
Preserve leverage.
- If there’s a seller delay or material nonconformity, document it (emails, notices, photos, promised specs vs. actual). This strengthens an Art. 1191 / PD 957 position.
Send a formal demand or negotiate.
- For Maceda: request cash surrender value, reference years paid, tender unit turnover/cancellation.
- For contract withdrawal: request penalty moderation, propose a mutual rescission with agreed refund.
- For seller breach: send notice of rescission citing grounds and demand refund within a defined period.
Notarial notice and compliance.
- Maceda cancellations require notarial notice. Keep proof of service.
- Developers also typically require cancellation processing (forms, IDs, original receipts).
Consider assignments (“sell to assume”).
- Many CTS allow assignment of rights to a new buyer (subject to seller/developer approval and fees).
- If refund is weak, an assignment can recover more of your 70% from the incoming buyer.
Escalation/Regulatory help.
- For developer projects: file with DHSUD (formerly HLURB) if negotiations stall, especially for PD 957 issues or Maceda disputes.
Litigate only if needed.
- File for rescission/damages (Art. 1191) or for refund enforcement. Courts may reduce penalties and award interest. Build a complete record.

6) Special issues & common misconceptions

“70% paid means I can just back out and get 70% back.” Not necessarily. Percentage paid is different from Maceda’s year-based formula or contract penalties.
“No Deed, so there’s no contract.” Often false. The CTS is binding. The Deed is the transfer instrument, not the source of the obligation (except in some private sales structured differently).
“I can invoke Maceda for commercial units or parking slots.” Maceda protects residential installment buyers. Coverage for non-residential assets is not the same.
“PD 957 guarantees refunds if I simply change my mind.” PD 957 mainly targets developer violations, not buyer’s convenience.
Penalties are always enforceable as written. Courts can reduce unconscionable liquidated damages (Civil Code Art. 1229). Keep that arrow in your quiver.

7) Document checklist (to cancel or to negotiate well)

Reservation Agreement and CTS (with annexes/specs)
Payment ledger and ORs (official receipts)
Notices from the seller (demand, cancellation, turnover)
Timeline proof (when you reached 2+ years of installments)
Marketing materials vs. delivered specs (if breach alleged)
Communications and photos (delays, defects)
Any proposed Assignment of Rights form (if you plan to assign)

8) Sample decision tree (quick triage)

Residential + installment + ≥2 years paid? → Yes: Use Maceda. Compute cash surrender value; send notarial cancellation request. → No: Go to next box.
Is seller in breach (delay, nonconformity, violations)? → Yes: Consider Art. 1191 or PD 957 complaint; demand full/near-full refund + damages. → No: Pure contract withdrawal—negotiate penalties, explore assignment of rights.

9) Frequently asked “what ifs”

What if I took possession already? Return of possession keys into restitution. If Maceda applies, you still compute cash surrender value; if contract withdrawal, expect use/occupancy charges to be offset.
What about bank financing? If you’ve availed of a loan (take-out), you’re past CTS. Cancelling now means prepayment penalties, loan closure, and coordinating reconveyance—far more complex than cancelling before DOAS/take-out.
Can the seller cancel on me and keep everything? Sellers must observe statutory and contractual process (e.g., notarial cancellation, grace periods under Maceda). Over-broad forfeitures can be struck down or reduced.

10) Bottom line

You can cancel before the Deed; your refund depends on the applicable law (Maceda vs. Civil Code/contract) and facts (years paid, seller breach).
If you’re a residential installment buyer with ≥2 years paid, Maceda is your anchor: expect 50%+ cash surrender value (capped at 90%), subject to statutory procedures.
If Maceda doesn’t apply, push for a mutual rescission with moderated penalties, or assert seller breach to seek fuller restitution.
Always paper your file, compute scenarios, and negotiate—and escalate (DHSUD/courts) if needed.

This overview is for general information and strategy planning in the Philippine setting. For specific contracts and remedies, consult a lawyer to review your documents, payment history, and seller conduct.