Buying off-plan in Porto safely: the buyer's safeguards

Buying off-plan means committing to an apartment before it physically exists, so your protection is contractual — and it lives in 3 documents. The reserva holds the unit; the CPCV (contrato-promessa) is the binding promise that carries the sinal deposit, indicatively 10 to 30% of the price; the escritura is the final deed, where 0.8% Imposto do Selo falls and ownership transfers. Only the escritura makes you the owner — the reserva and the CPCV are promises. The single most important safeguard is having an independent Portuguese lawyer read the CPCV before you sign it.

I'm Inês, and I work on the costs and contracts behind buying at Privilege Gardens, which delivers in 2027 — so this is written for a buyer committing before completion. This is orientation, not legal advice; the disclosure and the "verify with a lawyer" note are at the end.

The contract chain: reserva, CPCV, escritura

Off-plan in Portugal runs through 3 documents, and each locks something different (Lexidy; Global Citizen Solutions, 2026).

The reserva is a short reservation: it takes the unit off the market against a small fee, usually for a few weeks, while your lawyer does due diligence. The CPCV — contrato-promessa de compra e venda — is the binding promissory contract. It carries the price, the delivery date, the payment schedule and the sinal deposit, and it is the document that actually protects you. The escritura is the final public deed before a notary: you pay the balance, the 0.8% Imposto do Selo is settled and ownership legally transfers. Only the escritura makes you the owner — the new title is then entered at the Conservatória do Registo Predial.

The sinal and its double-back force

The sinal is the deposit you pay on the CPCV, indicatively 10 to 30% of the price (Lexidy, 2026), and its legal force is what makes off-plan workable. Under the Portuguese Civil Code it is a sinal in the strict sense, which carries a symmetrical remedy: if the buyer walks away without cause, the sinal is forfeited; if the developer defaults, the buyer can demand twice the sinal back.

If the developer defaults, you can claim back twice the sinal — that doubling is what gives the deposit real teeth.

That doubling is set out in Código Civil art. 442.º and is why the deposit, not the brochure, is the real instrument here. A larger sinal gives the developer more comfort but raises your exposure if the project stalls, so the size of the sinal is itself a negotiation, not a fixed rule.

Check the licence and the developer's title

Two public registries do most of the safety work, and your lawyer pulls both before you pay anything.

The construction licence (licença de construção) is issued by the Câmara Municipal do Porto and confirms the project is approved to be built. Ask to see it and note its number; a project being marketed without a granted licence is a flag. The Conservatória do Registo Predial (Land Registry) shows the property description, the current owner and any charges or mortgages — your lawyer reads the certidão permanente to confirm the title is clean and the developer actually owns what it is selling. These 2 checks, run together, catch the most common off-plan problems before money moves.

Stage payments and what to write into the CPCV

Off-plan is rarely paid in one go. Payment is usually staged across the build — a first slice at the CPCV, then tranches tied to construction milestones, with the balance at the escritura. The discipline is to tie each payment to a verifiable stage, not a calendar date the developer controls.

Four terms buyers most often regret leaving out:

What to secure in the CPCV	Why it protects you
A firm delivery date	Without it, "2027" is an aspiration, not an obligation
Late-delivery penalties	Turns a slipped date into a cost the developer bears
Milestone-linked payments	You pay for progress, not for a promise
A snagging window	Lets you inspect and have defects fixed before final payment

What is not written into the CPCV is not owed. Negotiate these with your own lawyer — not the seller's — and confirm the unit description and the finishes specification while you are at it.

What it costs, and when

Most one-off costs land at the escritura, not the reserva — so budget them from the start, alongside the staged construction payments. The table below is illustrative and pre-fee; confirm every figure with your counsel (Portal das Finanças; IRN; Lexidy, 2026).

Cost at the deed	Indicative amount	Notes (source)
Imposto do Selo (stamp duty)	0.8% of the price	Resident and non-resident, identical (Portal das Finanças)
Stamp duty on a mortgage	0.6% of the loan (≥5 yr)	Only if you take a Portuguese mortgage (Tabela Geral IS verba 17)
Casa Pronta deed + registry	≈ €375 (cash purchase)	The IRN one-stop; ≈ €700 if mortgaged
Independent conveyancing lawyer	~1 to 1.5% of price	A market norm, not a tariff — advisable off-plan (Lexidy)

The 0.8% Imposto do Selo is the one figure safe to state plainly: it applies at the escritura, to resident and non-resident buyers alike. IMT, the transfer tax settled at the same deed, is a different matter — a non-resident now pays a flat 7.5% headline rate under the 2026 law, but the exact euro effect, the bands and any relief depend on your situation and must be confirmed with a Portuguese tax lawyer. The full step-by-step of the purchase, from NIF to registo predial, is set out in the buying-process guide for Antas, and the one-off tax and fee load for an overseas buyer is broken down in non-resident buying costs in Porto. For why Antas itself is worth committing to ahead of delivery, see the 2027 catalysts.

The honest limits

This article is orientation for a buyer, not legal or tax advice, and it deliberately stops short of euro tax figures beyond the 0.8% stamp duty — those depend on your residency and on a law that changed in 2026. Have an independent Portuguese lawyer review the CPCV before you sign and confirm your own situation with a Portuguese tax lawyer. We develop in Antas, so we have an interest in how this reads; that is exactly why the safeguards here are the buyer's own, the figures carry their sources, and where the honest answer is "ask your lawyer," we have said so.

• Is it safe to buy an off-plan apartment in Portugal?+

  It is a normal, well-regulated way to buy, but the safety is contractual rather than automatic. Your protection sits in the CPCV (contrato-promessa de compra e venda): the sinal deposit with its double-back remedy, a fixed delivery date, late-delivery penalties, stage payments tied to construction milestones and a snagging window. Before you pay anything, an independent Portuguese lawyer should verify the construction licence and confirm the developer's clean title at the Land Registry. Off-plan carries real completion and timing risk, so the CPCV review is essential.

• What is the sinal and how does the double-back remedy work?+

  The sinal is the deposit you pay when you sign the CPCV — indicatively 10 to 30% of the price. Under the Portuguese Civil Code it is a sinal in the legal sense, which carries a symmetrical remedy: if you, the buyer, walk away without cause, you forfeit the sinal; if the developer defaults, you can demand twice the sinal back. That doubling is what gives the deposit real teeth, and it is why the CPCV terms matter more than the brochure.

• What are the three contracts when buying off-plan?+

  The reserva, the CPCV and the escritura. The reserva is a short reservation that takes the unit off the market against a small fee. The CPCV — contrato-promessa de compra e venda — is the binding promissory contract: it carries the sinal, the price, the delivery date, the payment schedule and the penalties. The escritura is the final public deed before a notary, where the balance is paid, 0.8% Imposto do Selo falls and ownership actually transfers. Only the escritura makes you the owner; the new ownership is then registered at the Conservatória do Registo Predial.

• How do I check the developer and the building permit?+

  Two public registries do most of the work. The construction licence (licença de construção) is issued by the Câmara Municipal do Porto and confirms the project is approved to be built; ask to see it and its number. The Conservatória do Registo Predial (Land Registry) shows the property's description, the current owner and any charges or mortgages against it — your lawyer pulls the certidão permanente to confirm the title is clean before you pay. Both are standard due-diligence steps an independent lawyer runs for you.

• What should I put in the CPCV before signing?+

  Four things buyers most often regret leaving out: a firm delivery date, penalties for late delivery, the stage-payment schedule tied to verifiable construction milestones, and a snagging window to inspect and have defects fixed before final payment. Also confirm the unit description, the finishes specification and what happens to your sinal if the project is delayed beyond the agreed date. What is not written into the CPCV is not owed, so this is the document to negotiate, with your own lawyer, not the seller's.

• When do I pay the taxes and fees on an off-plan purchase?+

  Most one-off costs land at the escritura, not the reserva. Imposto do Selo (stamp duty) of 0.8% on the price is paid at the deed, and IMT (the transfer tax) is settled then too — its rate depends on whether you are resident or non-resident and should be confirmed with a Portuguese tax lawyer. The Casa Pronta one-stop deed-and-registry is roughly €375 for a cash purchase, and an independent conveyancing lawyer typically charges 1 to 1.5% of the price. Budget these from the start, alongside the staged payments during construction.

Sources & method⌄

1. Lexidy (law firm) — buying property in Portugal: CPCV, sinal, due diligence and the deed
2. Global Citizen Solutions — the Portuguese property purchase process (reservation → promissory contract → deed)
3. Código Civil português, art. 442.º — regime do sinal (the double-back remedy)
4. Portal das Finanças — Tabela Geral do Imposto do Selo (0.8% on the transfer; 0.6%/0.5% on the mortgage)
5. Portal das Finanças — Código do IMT, art. 17.º (flat 7.5% rate for a non-resident acquirer)
6. IRN / Justiça.gov.pt — Casa Pronta deed-and-registry costs (verify the current euro fee)
7. Câmara Municipal do Porto — urban licensing (licença de construção)
8. Instituto dos Registos e do Notariado — Registo Predial (certidão permanente / clean title)