Buying an undivided share: know what you own

The listing says “left-hand house”, “first floor” or “half the land”. At the viewing, each family uses a separate entrance and courtyard. The land-register certificate may tell a different story: the seller owns an undivided share of one property, not exclusive legal ownership of that physical space.

If you buy the share, you become a co-owner of the whole. Before paying a deposit, confirm exactly which right is registered, what agreement permits use of the space shown, and which risks remain shared.

A share is not the physical half you were shown

Article 1403 of the Portuguese Civil Code defines co-ownership as two or more people simultaneously holding ownership of the same thing. Their shares may differ — 1/2, 1/3 or 1/6, for example — but each relates to the common property.

That is different from an autonomous unit under horizontal property. The title of an autonomous unit identifies a legally separate asset, such as apartment A. With an undivided share, “50%” measures the co-owner's participation in the right over the entire property; it does not draw a line through the house.

Article 1408 makes the practical difference clear: a co-owner may transfer their share but cannot sell or encumber a specified part of the common thing without the other co-owners' consent.

Do not confuse co-ownership with an estate that has not yet been divided. The current owners may have acquired the home through succession, but the completion professional must first identify whether you are buying a registered property share or an interest in an undivided estate. The process and documents differ.

Start with the permanent certificate, not the listing plan

The Portuguese land register shows the legal status of property, including its composition, ownership and burdens. The permanent certificate includes registrations in force and pending applications. Obtain a current access code before reserving and check it again near completion.

Then compare the certificate with the caderneta predial, or property tax record. According to the Portuguese Tax Authority, the caderneta identifies the property, location, characteristics, owners and taxable value. It is a tax-record document, not a substitute for registry proof of the legal status.

Also compare the description with plans, the use licence or planning title, any survey and the situation on site. If the listing promises a separate home or parcel, find the document that made it legally separate. An electricity meter, private door or tax entry for a “division with independent use” should not be treated, without review, as proof of an autonomous unit.

“Exclusive use” needs documents and clear limits

Co-owners may organise between themselves who uses each area. That agreement can be important in daily life, but it should not be presented as if it had automatically created two autonomous properties.

Without an agreement, article 1406 allows each co-owner to use the common thing, provided they respect its purpose and do not deprive the others of the use to which they are also entitled. The same article says that using the common thing does not by itself constitute exclusive possession or possession of a larger share.

If you depend on an agreement to occupy the area shown, ask your lawyer to confirm:

• who signed and whether all current owners are bound;
• which plan identifies areas, access, parking and meters;
• whether use is exclusive, alternating or shared;
• how the roof, facade, structure, insurance and works are decided and paid;
• whether you may let, alter or equip the space;
• what happens when a share is sold, inherited, attached or divided;
• how breaches and deadlocks are resolved.

A useful agreement reduces operational uncertainty. It does not by itself cure unlicensed works, prohibited subdivision, missing permissions or inconsistency between registry, tax record and reality. Connect this review with the checks on planning title and land boundaries where relevant.

Clear the right of first refusal before buying as an outsider

When a share is sold to someone who is not already a co-owner, the other co-owners may have a statutory right of first refusal. Article 1409 gives them first place among statutory preference holders when a share is sold or given in payment to an outsider.

Do not reduce this to a generic contract checkbox. Before completion, the lawyer, notary or solicitor should confirm who must be informed, which essential deal terms must be communicated, which deadlines apply and what evidence will remain in the file. A change to the price, conditions or asset may make an earlier communication inadequate.

This issue is related to, but different from, preference rights held by tenants, municipalities or adjoining owners. Read the guide to rights of first refusal and obtain a combined review of the preference holders relevant to the property.

Do not rely on future division or automatic mortgage approval

Article 1412 provides that a co-owner is not normally required to remain in indivision. An indivision agreement may apply for up to five years and may be renewed; for real property, it must be registered to bind third parties.

Division may be agreed or follow the legal process. That does not guarantee the buyer will eventually receive the kitchen, floor or plot they had been using. Physical division may be impossible or conflict with planning rules; the result may involve adjudication, balancing payments or sale, depending on the facts and applicable decision. Buy only if you accept the right that exists now, not an informal promise to “legalise it later”.

Apply the same discipline to the lender. General pre-approval mainly assesses the borrower; it does not mean this share and structure will be accepted as security. Before paying a deposit, give the lender:

1. the permanent certificate and tax record;
2. plans and available planning title;
3. the use agreement and signatures;
4. the draft CPCV with the correct share;
5. information about other owners, occupiers and burdens.

Ask for written confirmation of valuation, finance amount, buyer equity, missing documents and conditions that must be satisfied before completion.

Make the CPCV sell the real share, not the marketing description

The CPCV should identify the property, seller and share exactly as they appear in the register. If your decision depends on use of a physical area, attach the agreement and plan to the contract; do not leave that dependency in an agent's message.

Avoid a vague clause saying only that the seller “will arrange horizontal property”. Define the documentary result required, who obtains it, who pays, the final date and what happens to the deposit if the condition fails. Creating autonomous units or dividing land depends on requirements the parties cannot satisfy through contractual intention alone.

Next step

Write what you were shown and what the certificate sells in two columns. If one says “left-hand house” and the other says “undivided 1/2 of the property”, send the certificate, tax record, plan, use agreement and draft CPCV to your lawyer and lender before paying a reservation or deposit.