Real estate due diligence in Portugal 2026: documents, risks, and legal due diligence

Due diligence isn't a formality, but protecting your money

Legal due diligence on real estate in Portugal isn't a bureaucratic whim, but a way not to hand your money over to someone else's problems. Outwardly the deal is simple: you find a property, agree on a price, sign a preliminary contract, pay a deposit, and come to the notary for the final deed a few weeks later. But it's exactly in the interval between "liked it" and "signed at the notary" that all the real work happens.

The thing is, in Portugal many property problems aren't visible at a viewing. The apartment can be mortgaged at a bank, the house can have an illegal extension or attic not reflected in the documents, and the seller can have unpaid condominium dues that will fall on the new owner after the deal. The area per the documents may not match reality. The notary certifies the fact of the deal, but doesn't conduct a deep check of the property's cleanliness for you - that's the buyer's and their lawyer's responsibility.

So the rule is simple: check first, money second. It makes sense to sign the preliminary contract and pay the deposit only after the property has passed the check on key documents. We break down the basic logic of the purchase itself in a separate article onbuying real estate in Portugal- the focus here is exactly on how not to buy a pig in a poke.

Certidao Permanente do Registo Predial: the main document on cleanliness

If the check has a heart, it's the Certidao Permanente do Registo Predial - the land registry extract (Conservatoria do Registo Predial). This is an analog of a title registry extract, and it's exactly this that answers the main question: who genuinely owns the property and what's "hanging" over it.

What the registry extract shows:

• The current owner.Whether the seller matches who's registered as the owner. If a "representative" is selling the apartment, a correct power of attorney is needed.
• Mortgages (hipoteca).Whether the property is mortgaged at a bank. Mortgaged real estate can also be bought, but the mortgage must be repaid and lifted by the time of the deal.
• Encumbrances and seizures (onus, penhora).Judicial seizures, tax liens, third-party rights, easements.
• The history of ownership transfers.The chain of previous owners and grounds.

The extract is issued online and valid for a limited time, so it's always obtained as fresh as possible - ideally right before signing. One of the most dangerous scenarios is when the seller shows an old certificate, and a seizure has appeared on the property in the months since. So the lawyer rechecks the registry again right before the notarial deed.

An important detail, approximate: real estate with an unrepaid mortgage can also be sold in Portugal, but the debt sum is paid off from the deal's price, and lifting the lien is recorded. The deal can't proceed without confirmation the encumbrance was lifted.

Caderneta Predial: the property's tax passport and area

The second key document is the Caderneta Predial Urbana, a tax cadastral document from the tax authority (Autoridade Tributaria, Financas). If the Certidao Permanente is about rights and encumbrances, the Caderneta Predial is about how the property is described for tax purposes and whether this matches reality.

What's important to check in the Caderneta Predial:

• The property's description.Type (apartment, house, plot), floor, number of rooms, designated use (residential/commercial).
• Area.The cadastral area must match what you see and what's recorded in the registry. Discrepancies are a reason to ask questions.
• The taxable value (VPT).The annual municipal IMI tax and the IMT transfer tax at purchase are calculated from it.
• The registration number (artigo matricial).The cadastral identifier, which must match the registry extract.

The main risk this document reveals is a mismatch between the property's actual state and its description. A classic example: a living room has been set up in place of a declared storage room or terrace, or the house is actually larger than registered. This is a signal of possible unauthorized alterations that will later need to be legalized at your own expense.

The deal's tax side is a separate large topic, and it's worth studying in advance in our article onreal estate taxes in Portugal, to understand how VPT affects your future expenses.

Licenca de utilizacao: is it even legal to live here

The third document, without which it's impossible - licenca de utilizacao (for old properties it's called licenca de habitacao), that is, the use (habitation) license. This is a permit issued by the municipality (Camara Municipal) confirming: the building was built to the project, has been commissioned, and is fit for its declared use - residential or commercial.

Why this is critical:

• Without the license, the property can't legally be used for its purpose.The notary generally requires it to process a housing deal.
• The designated use must match.If you're buying housing, the license must be residential. Converting a commercial space to residential is a separate, slow procedure.
• The construction year determines nuances.For buildings built before 1951, the use license historically may not have been required - a special certificate is issued in such cases.

The main risk this document closes off is buying a property that's effectively illegal or unfinished in terms of permits. It happens that a house is finished, people live in it, but it was never officially commissioned. The buyer of such a property will then have to independently go through legalization, and that's money, time, and not always a guaranteed result.

Layout compliance is checked separately: if walls in the apartment have been demolished or erected, rooms combined, a balcony glazed in - these alterations must be reflected in the documents or legalized.

The energy certificate: mandatory and affects expenses

The energy efficiency certificate (Certificado Energetico) in Portugal is a mandatory document for selling and long-term renting real estate. Without a valid energy certificate, a property can't legally be listed for sale, and it's required when processing the deal.

What to know about the energy certificate:

• The class scale.From A+ (the most energy-efficient) to F (the least efficient). The class reflects insulation, windows, heating and cooling systems.
• Who issues it.An accredited energy auditor; the certificate is registered in the ADENE system.
• Validity term.The certificate is valid for a limited time (for housing approximately up to 10 years) - check it's not expired.

Why does the buyer need this beyond formality? A low energy class (E or F) directly means high heating and cooling bills and potential insulation expenses. Additionally, the energy class affects some tax and rental parameters. So the certificate isn't just paper for the deal, but an indicator of future operating costs, worth factoring into price negotiations.

Condominium and tax debts: what passes to you

One of the most unpleasant surprises after a deal is other people's debts that suddenly become yours. In Portugal there are two types of these that are mandatorily checked before buying.

Condominium debts (condominio).If you're buying an apartment in a jointly managed building, the seller may have unpaid monthly dues and shares in common expenses (facade repair, the elevator, the roof). An important point: condominium debt is tied to the property, and the new owner can end up responsible for debts accumulated before the deal. So a certificate is requested from the manager (administrador do condominio) confirming no debt (declaracao de nao divida), as well as meeting minutes - to find out about planned major expenses and special assessments.

Tax and utility bill debts.It's checked whether the annual municipal IMI tax has been paid, whether there are tax liens, whether water, electricity, and gas bills are settled. Tax debts can transform into an encumbrance on the property.

What we check in this block:

• A certificate of no condominium debtand the amount of monthly contributions.
• General meeting minutes- whether there are approved expensive repairs that will fall on the new owner.
• IMI paymentand no tax liens.
• Closing utility billsas of the transfer date.

These checks seem like small things, but it's exactly unpaid dues and a forgotten special assessment for facade renovation that most often spoil the joy of a new apartment.

The Alojamento Local (AL) license: if you plan to rent to tourists

A separate and, for many investors, decisive question is whether the property can be rented daily to tourists through Airbnb and similar platforms. In Portugal this requires the Alojamento Local (AL) license, and having it or the ability to obtain it can't be taken for granted.

Key points on AL:

• AL is the registration of a specific propertyfor short-term tourist rental, with its own number.
• It can't be obtained everywhere.In a number of popular zones in Lisbon, Porto, and other cities, restrictions and moratoriums have been introduced on new AL licenses - in so-called "restriction zones".
• If the property already has a valid AL- it's checked whether the license is valid and not suspended; transferring AL to the new owner has its own conditions.
• Regulations have changed.The Mais Habitacao reform introduced restrictions on AL, some of which were subsequently revised - the current status for a specific address needs to be checked separately (approximate).

For an investor buying an apartment specifically for rental income from tourists, being unable to get AL can undo the deal's entire economics. So if the business model is built on short-term rental, checking the AL status for the specific address is a mandatory item even before the deposit. We break down the overall return and strategy picture inour guide to investing in Portuguese real estate.

The lawyer's and notary's roles: who's responsible for what

In a Portuguese deal, the lawyer (advogado) and the notary (notario) have different roles, and understanding this difference means not being left unprotected.

Notarycertifies the deal: checks the parties' identities, the presence of basic documents, the deed's correctness, and certifies signatures. But the notary is neutral and doesn't represent your interests. They don't negotiate for you, don't assess the property's risks in depth, and aren't responsible for whether the deal is advantageous to you.

A lawyerworks on your side. It's exactly them who:

• Conducts a full check (due diligence) of all documents - the registry, cadastre, licenses, debts.
• Checks the seller's authority and the authenticity of powers of attorney.
• Drafts or reviews the preliminary CPCV contract and the final deed, protecting your terms on the deposit and deadlines.
• Controls mortgage repayment and lifting encumbrances by the time of the deal.
• Supports getting the Portuguese NIF tax number and opening an account, without which the deal can't be closed.

A foreign buyer almost always needs an independent lawyer with no ties to the seller or the agency. Too many nuances are hidden in the language of documents and local practice. Saving on a lawyer is the most costly saving in a Portuguese deal, because the price of a mistake is measured not by their fee, but by the whole property's value.

The preliminary CPCV contract and deposit: where obligations arise

The central moment of a Portuguese deal is the preliminary purchase-sale contract, Contrato de Promessa de Compra e Venda (CPCV). This isn't a "note of intent", but a legally binding document, after signing which you can't simply back out.

How the CPCV and deposit (sinal) work:

• The CPCV recordsthe property, price, timeline to the final deal, conditions, and the deposit sum.
• The deposit (sinal)is usually 10-30% of the price and is paid on signing the CPCV (approximate - the specific percentage is negotiable).
• If the buyer backs out of the deal- the deposit is generally forfeited to the seller.
• If the seller withdraws- they're generally obligated to return the deposit doubled.

It's exactly because of this mechanic that it's critical to conduct the whole check BEFORE signing the CPCV. Having signed the preliminary contract and paid the sinal, you're already tied by money: finding a problem after this (a seizure, an unauthorized extension, no AL), you risk losing the deposit or getting stuck in a dispute.

A good CPCV protects the buyer with clauses: for example, a condition to return the deposit if encumbrances are found or if the bank refuses the mortgage. If you're buying with a loan, these conditions are especially important - see financing details in our article ona mortgage for foreigners in Portugal.

Risks of new builds and unfinished construction

Buying at the construction stage (off-plan) or from a developer is a separate risk category, different from the secondary market. The property doesn't exist yet or isn't finished, and money is paid in stages.

What to look at when buying a new build:

• The building permit (licenca de construcao)and project documentation - whether the property is being built legally.
• The developer's reputation and financial stability- the history of delivered projects, the risk of bankruptcy and a construction freeze.
• A future use license.Before its issuance, the property can't be commissioned - deadlines and guarantees must be stated in the CPCV.
• The payment schedule,tied to construction stages, and return guarantees in case of delayed deadlines.
• Warranty obligationsthe developer's warranty on structure and finishing.

The main risk of unfinished construction is paying for a property that's unfinished or finished with violations, and ending up with no use license. So in new-build deals, legal protection is especially important: staged payment strictly by actual readiness, clear deadlines in the contract, and checking all the developer's permits. Buying a "foundation pit" from a beautiful rendering with no document check means taking on risks that simply don't exist on the secondary market.

Typical mistakes of foreign buyers: an expert's view

Over years of supporting deals in Portugal, we see that foreigners are let down not by rare things, but the same recurring mistakes. Let's break them down so you don't make them.

• Paying the deposit before the check.The most costly mistake. Having signed the CPCV and paid the sinal, you're already tied by money - a problem found later is hard to fix, and the deposit can be lost.
• Trusting an old registry extract.The Certidao Permanente is obtained as fresh as possible and rechecked right before the deal - seizures and mortgages appear quickly.
• Ignoring condominium debts.An innocent-looking apartment can drag behind it unpaid dues and an approved expensive facade repair.
• Not checking the area and extensions.Extra square meters often actually mean unauthorized alterations that will fall on the new owner.
• Counting on AL with no check.In restriction zones, a new short-term rental license may simply not be issued - and the investment model collapses.
• Relying on the notary as a protector.The notary certifies the deal, but the buyer's interests are protected only by their own independent lawyer.

The Portuguese real estate market forgives slowness, but doesn't forgive haste and carelessness. The more thorough the check before the money, the calmer life after the deal.

Bottom line: how to buy real estate in Portugal safely

Safe real estate purchase in Portugal in 2026 is built on a simple sequence: first a full check of the property, then the preliminary contract with a deposit, and only then the notarial deed and payment. Skipping the check, giving in to excitement or the seller's pressure, means taking on someone else's risks.

The minimum set of documents that must pass through your lawyer's hands is unchanged: the Certidao Permanente registry extract for encumbrances, the Caderneta Predial tax cadastre for area and description, the use license for legality, the energy certificate, certificates of no condominium and tax debt, and for investment rental - the AL license status. For a new build, permits and the developer's financial stability are added.

We always advise a foreign buyer to work with an independent lawyer who represents specifically your interests, not the seller's or the agency's. This isn't an extra luxury, but basic capital protection. If you're eyeing a specific market, for example the capital, study its specifics in our article onreal estate in Lisbon, and always check current administrative requirements and forms on the official portal ofPortugal's government services (gov.pt).

Area, extensions, and the legality of alterations

A separate layer of the check is whether what you see matches what's recorded in the documents. Discrepancies here occur more often than it seems, and cost dearly.

What's checked:

• Area by fact, by cadastre, and by registry.All three values must agree. If the actual area is larger than declared, unauthorized extensions are possible.
• Extensions and additions.An attic, veranda, pool, garage, an extra floor - all of this must be reflected in the documents and have permits.
• Internal remodeling.Demolishing or erecting walls, combining rooms, converting non-residential to residential - alterations must be legalized.
• Plot boundaries for houses.Whether the real boundaries match the cadastral ones, whether there's no encroachment on neighboring land or, conversely, others' structures on your plot.

The main risk is buying a property with unauthorized alterations. After the deal, it's exactly you who will have to either legalize the extension (paid, slow, and not always possible) or demolish it under the municipality's order. In the worst case, illegal alterations also hinder selling the property in the future. So an experienced lawyer always compares the layout from the documents against reality at the viewing, and involves a technical specialist if in doubt.

The full due diligence checklist: document - what it reveals - risk

Let's put the whole check into a single checklist. This is the working framework the lawyer goes through the property with before you pay even a euro of the deposit. If there's no clarity on any point, the deal isn't rushed - the question is closed first.

This checklist isn't "paper insurance", but a real filter. Every line in it appeared from someone's costly mistake. By going through all the points before signing the CPCV, you turn a risky purchase into a controlled deal.