Co-buying Spanish property in 2026: siblings, unmarried partners, and small groups

Roughly one in five foreign purchases we see on Buvivo isn't a single household buying a home. It's two sisters splitting a village house their late father used to visit. It's a long-term unmarried couple with two kids who never got round to registering. It's three university friends chipping in for a Costa Brava flat they'll rotate through in summer. Prices have outrun single-buyer budgets, remote work has made the "shared holiday home" a serious asset again, and inheritance flows are pushing siblings into joint decisions their parents never had to make.

Spanish law is, on the whole, friendly to co-buyers. There is no rule that says two unrelated adults can't appear together on a deed, and there is no cap on how many people can hold a share. But the how — which ownership structure, which percentages, which mortgage, which exit clause — is where the wheels come off. And the fault lines are almost always the same three: what happens if one of you wants out, what happens if one of you dies, and what happens when the tax office looks at the deed and decides your quiet 50/50 split is a donación encubierta — a disguised gift.

This is the 2026 playbook. It won't replace a Spanish property lawyer — you need one — but it will let you walk into that first meeting knowing which questions to ask.

Three co-buyer scenarios we see most often

The paperwork changes with the relationship. Before anything else, work out which of these you are.

Siblings inheriting or pooling. Two, three, sometimes four adult children buying together, often as a bridge between generations: keeping the family home in Galicia, splitting a Málaga flat that mother lived in until she went into care, or clubbing together to buy a holiday base near cousins. Money is often unequal; use of the home is often unequal too.

Unmarried partners. Long-term couples with no matrimonio on record — sometimes registered as a pareja de hecho, more often not registered at all. The mortgage is joint, the deposit is often unequal, and the legal protection Spain grants married couples on death, divorce and taxation does not automatically apply.

Friends or small investor groups. Two to five buyers, usually foreign, buying a coastal or city flat as a rotating holiday home, an Airbnb project, or a plain rental investment. The relationships are strong on paper and fragile on the day someone gets married, changes country, or needs cash.

Each maps to slightly different tools. Almost all of them share the same starting point.

The default: proindiviso co-ownership

The moment two or more people appear on a Spanish escritura as buyers, without setting up anything more elaborate, they hold the property in comunidad ordinaria or proindiviso — undivided co-ownership. It is defined by articles 392–406 of the Civil Code and it is Spain's default answer to "several people bought one thing."

The mechanics are simple:

• The deed lists each owner and the percentage each holds. Percentages are almost always tied to who put up which share of the price, deposit included. Two siblings each paying half → 50/50. Three friends paying €80k, €60k and €60k → 40/30/30.
• Every decision on the whole thing (selling, mortgaging, gifting) needs unanimity. Every ordinary act of use and administration can be taken by the majority of shares, not heads.
• Each owner can freely sell, mortgage, or gift their own share to a third party — subject to a legal right of first refusal (derecho de tanteo y retracto) in favour of the other co-owners.
• Costs — the IBI, community fees, insurance, repairs — are shared pro rata to the share, not equally. If you own 40% you pay 40% of the €900 IBI.
• Any co-owner can force a division of the thing held in common (acción de división de la cosa común) at any time — Article 400. This is the nuclear option and it's important enough to deserve its own section below.

For most co-buys, proindiviso is the right tool. It's cheap to set up (nothing to set up — the deed does it), transparent, and the taxman understands it. What most buyers get wrong isn't the choice of structure; it's not thinking through Article 400 before they sign.

The alternative: a Spanish company (SL)

The other structure that comes up is buying through a Sociedad Limitada (SL) — a Spanish private company you incorporate for the purpose, with the co-buyers as shareholders.

The pitch sounds good: each shareholder owns shares, not a slice of a specific asset. Selling out means transferring shares, not carving up a deed. Bringing in a new partner is a share purchase. The company can be inherited without dragging the property through succession.

The reality in 2026 is that for most family and small-group co-buyers, an SL is overkill and expensive to run:

• Incorporation is €600–€1,200 plus a €3,000 minimum share capital.
• The company must file annual accounts, pay corporation tax (25% on rental profits, capital gains), and — crucially — the personal use of the flat by shareholders is treated by Hacienda as a retribución en especie, taxed as if it were rental income at market rate. Two weeks in August is a taxable benefit.
• Transfer tax when the company buys the property is the same as a personal buy (7–10% depending on region).
• On sale, capital gains sit inside the company; getting the cash out to shareholders costs another layer of tax.

The SL only stacks up when the property is a genuine investment — you're running it as a business, not using it personally — or when the group is large (five plus), or when there is significant estate-planning reason to want the property owned by a legal entity. For "we're three siblings and we want to share the summer house," proindiviso is almost always cheaper and cleaner.

Getting the percentages right — the deposit trap

This is the single most expensive mistake we see co-buyers make.

Two friends buy a €400,000 flat in Valencia. Ana puts down the €80,000 deposit; Beatriz puts up nothing until completion, when they take out a €320,000 joint mortgage in both names. They agree the flat is "half each," and the notary records 50/50 on the deed.

Hacienda's view: Ana just gave Beatriz €40,000 (half the deposit) as a gift, on which Beatriz owes impuesto sobre donaciones. The amount varies by region — Madrid: near zero after the 99% bonification; Valencia: painful — but the point is that a mismatch between what each person paid and what the deed records their share as is treated as a taxable transfer.

The fix is either:

1. Record the real percentages on the deed. Ana's deposit (€80k) plus half the mortgage (€160k) = €240k = 60%. Beatriz's half of the mortgage = €160k = 40%. 60/40 on the escritura, honestly.
2. Document a private loan. Ana lends Beatriz €40,000 to equalise the deposit, at a market rate of interest, formalised in a private loan agreement filed with Hacienda (Modelo 600, exempt because it's a family/personal loan at arm's length). The deed then records 50/50 legitimately, and Beatriz repays Ana over time.

Option 1 is much simpler and works for almost everyone. Option 2 is what you do when the co-buyers need the 50/50 optics — married-in-all-but-name couples, business partners.

Either way, make the percentages match the money. If you can't explain to a tax inspector why your share is what it is, you have a problem.

Unmarried partners — the pareja de hecho question

Spain gives married couples a set of automatic legal protections around jointly-held property: default marital regimes (sociedad de gananciales in most of Spain, separación de bienes in Catalonia and the Balearics), automatic inheritance rights, and preferential tax treatment on transfers between spouses. Unmarried couples get none of that by default.

Registering as a pareja de hecho (registered civil partnership) partially closes the gap — but only partially, and the exact rights depend on which region you register in. Catalonia and Andalucía offer near-marriage treatment on inheritance and IRPF joint filing; Madrid gives less; the national picture is a patchwork.

Practical implications for an unmarried couple co-buying:

• On death. Unless you have a Spanish will (testamento) that names your partner, your share of the flat passes to your closest blood relatives under intestate rules — your children first, then your parents, then your siblings. Your partner gets nothing automatically. Make a Spanish will before you complete on the property, or the same week.
• On split-up. There is no equivalent of divorce court to divide the flat "fairly." You are two co-owners under Article 400 (see below). If you can't agree, one of you sues to force the sale.
• On inheritance tax. Between unmarried partners without pareja de hecho registration, inheritance tax rates are the harshest tier (Group IV — 45% at the top, with almost no allowance). Even the same-day registration as pareja de hecho moves the couple into a friendlier tier in most regions.

If you're co-buying with an unmarried partner and you plan to live your life in Spain, the case for registering as pareja de hecho is essentially unanswerable. Get it done before the notary appointment.

The exit clause — Article 400 and the acción de división

This is the section most co-buyers wish they'd read before signing.

Article 400 of the Civil Code says: no co-owner is obliged to remain in a common ownership. Any co-owner, at any time, without cause, can force the cosa común to be divided.

For a flat — which physically can't be divided into slices — "dividing" means one of two things:

• Voluntary partition. The other co-owners buy out the exiting share at a price everyone accepts, or they sell the whole property and split the proceeds by share.
• Judicial sale. If the co-owners can't agree, the court orders a subasta pública — a public auction — of the entire property. The proceeds are split by share. This is a catastrophic outcome: auctions in Spain typically clear at 60–75% of open-market value.

Two consequences for a co-buyer:

1. You cannot contractually override Article 400 forever. You can, however, agree in a written pacto de indivisión — filed at the property registry — to keep the property undivided for up to 10 years, renewable. This is the single most valuable protection a co-buyer group can put in place, and hardly any of them do.
2. Draft a co-ownership agreement. Sitting alongside the pacto de indivisión, this private contract sets the rules: who has right of first refusal on a share (typically the other co-owners), how a buyout price is calculated (market appraisal by a tasador both sides accept, or the average of two), notice periods, what happens if a co-owner dies or divorces. It's the pre-nup of the joint deed, and its absence is why 90% of the co-owner disputes we see end up in court.

Every co-buy needs both documents. The pacto de indivisión protects everyone from the impulsive Article 400 filing. The co-ownership agreement resolves the disputes the pacto doesn't reach.

Mortgages as a group

Spanish banks are used to two-person mortgages — spouses, mostly. Three-person and four-person mortgages exist but the underwriting is different.

What we see in 2026:

• Every borrower is jointly and severally liable for the whole loan. If one co-buyer stops paying, the bank goes after the others for the full missing amount — not their percentage share. The bank does not care about the internal split.
• The bank looks at the weakest applicant. LTV, age, income multiples: the file is priced to the lowest-scoring co-buyer. Adding a strong second applicant to a marginal first does help; adding a third weak one hurts.
• Non-resident LTV is capped lower. Most Spanish banks lend 60–70% to a non-resident household, 70–80% to a resident one, and the mix matters. A couple where one partner has already moved to Spain and one hasn't is often priced as non-resident on the higher-earner alone.
• Life insurance is normally required for each borrower, on the full loan. Not on each borrower's share — on the whole balance. Two co-borrowers each carry two policies at 100%. It's expensive and it's not optional.
• Refinancing when someone leaves is painful. Removing a borrower from a Spanish mortgage means the bank re-underwrites the entire loan on the remaining borrowers, plus a novación fee, plus the exiting borrower usually has to be bought out of their share at the same time — a fresh escritura and full transfer tax on the share transferred (though a disolución de condominio between the same co-owners is charged at 1.5% AJD, not the full 7–10% ITP — an important saving).

Read our full non-resident mortgage guide before you approach a bank as a group. Talk to a broker who has actually placed three-name files — most haven't.

Tax exposure for co-owners

The good news: as long as your ownership percentages match your contribution, the tax picture is mechanical. Each co-owner pays their percentage of everything.

• Modelo 210 — non-resident owners each file their own return, on their share of the imputed rent (empty period) or actual rent (let period). Three co-owners = three annual filings.
• IBI and rubbish tax — the town hall bills the property once. The co-owners settle pro rata internally (or one pays and reclaims from the others).
• Wealth tax — each co-owner declares their share of the property value against their own regional allowance. Spreading a €1.2M flat across three siblings often keeps everyone under the wealth-tax threshold in a way single ownership wouldn't.
• Capital gains on sale — each co-owner reports their share of the gain against their purchase cost and their residency status. If one co-owner is Spanish-resident and one is not, the resident pays 19–28% progressive; the non-resident pays a flat 19% (or the sale withholds 3% and refunds the difference).
• Rental income — split pro rata by ownership, filed by each owner. IRPF for residents, Modelo 210 for non-residents.

The worst thing you can do is under-declare one co-owner's share to reduce total tax. Hacienda cross-checks against the deed. The deed is public. Don't.

Inheritance planning across the co-owners

Nobody wants to talk about this at the notary and everybody should.

Under Spanish forced-heirship rules, a resident co-owner's share on death passes largely to their children (two-thirds is reserved for descendants), then spouse, then ascendants. A non-resident co-owner can, since the Brussels IV regulation, elect their national inheritance law in their will — a British co-owner can elect English rules and dispose of their share freely.

The scenarios that go wrong:

• Sibling co-owner dies childless, intestate. Their share goes to their parents (if living), then to their siblings — which may include the co-owners already on the deed. Convenient. But: siblings inheriting from siblings sit in Group III for impuesto sucesiones, with limited allowances. The tax bill can be brutal.
• Unmarried co-buyer dies without a Spanish will. Their share goes to their blood relatives. The surviving partner is now co-owning with parents they may barely know, in a jurisdiction they don't live in. Article 400 fires almost immediately.
• Sibling co-owner with children dies. Their share splits among the children (usually minors). The surviving sibling is now co-owning with two nephews and a niece, one of whom will hit majority in 12 years and can invoke Article 400. Plan for this or plan to be forced to sell.

The tool for every co-buy is: each owner makes a Spanish will covering their Spanish assets, ideally within 30 days of completion. The will can be short (one page), it's cheap (€50–€80 at the notary), and it locks in the successor law under Brussels IV. Do this immediately.

The costs of splitting up later

The cheapest split is the one you plan on day one. Roughly, in 2026:

Exit route	Typical cost	Notes
Sell whole property, split proceeds	Standard sale costs (2.5–4% incl. agent, notary, capital gains)	Cleanest. Requires unanimity or majority-share vote.
Disolución de condominio — one co-owner buys the others out	1.5% AJD on the value of the share transferred + notary + registry	Cheapest transfer route between existing co-owners.
One co-owner sells their share to an outsider	7–10% ITP on that share paid by the buyer + notary	Other co-owners have right of first refusal.
Judicial partition / auction	5–8% court and expert fees + 25–40% market discount at auction	Worst outcome. Avoid at all costs.

The disolución de condominio is the underappreciated hero here. If one sibling wants out and the other two want to keep the flat, moving the leaver's share to the stayers is not a sale — it's a dissolution of joint ownership. AJD at 1.5%, not ITP at 8–10%. On a €400,000 flat, that's the difference between €6,000 and €32,000 in transfer tax.

A minimum paperwork checklist before you sign

For any co-buy, non-negotiable:

• Percentages on the deed that match the money. Deposit, mortgage, fees — mapped and documented.
• A nota simple — pulled the week of signing, checked by your lawyer.
• A pacto de indivisión — signed by all co-buyers, filed at the property registry, locking in undivided ownership for 10 years.
• A private co-ownership agreement — right of first refusal, buyout mechanic, decision-making rules, use of the property (rotating weeks? high-season priority?), who pays what.
• A Spanish will for every co-owner — made within a month of completion.
• Life insurance for each mortgaged co-owner — bank will require it; think about topping up above the minimum.
• A Spanish bank account for each co-owner — Hacienda expects individual filings from individual accounts.
• NIE numbers for everyone — before you sign anything.
• If unmarried partners: registration as pareja de hecho in the relevant regional register, ideally weeks before completion.
• A single lawyer, or coordinated lawyers. One property lawyer representing the group is cheaper; conflicts of interest can arise when the group disagrees. Get the conflict-management terms in writing at the start.

How Buvivo fits a co-buyer group

The awkward reality of shopping for a co-buy on a portal is that no single filter can capture the group's combined criteria. Three siblings looking for a Málaga base each have different maximum drives to the airport, different sensitivity to noise, different views on whether a lift is a must. That shows up as three parallel Idealista searches, three different agent lists, and no way to coordinate the shortlists.

Reverse search fixes this. Post one request, list the criteria that survived the group's Zoom meeting, and let agents come to you with properties that hit all of them. When the group needs to argue about a specific listing, everybody is looking at the same shortlist from the same feed — not three private portals.

Agents also read a co-buyer request as high intent. A group that has already agreed on a budget, a region, a max drive time and a bedroom count has done more work than 80% of solo buyers. The best listings surface faster when your request is that specific.

Further reading

• The complete buyer's guide to property in Spain for foreigners
• Spanish inheritance tax and wills for foreign property owners in 2026
• Comunidad de propietarios: the community of owners explained
• Spanish mortgages for non-residents
• Spanish property lawyer: what a good one does for you

This article is a general guide, not legal or tax advice. Spanish co-ownership rules and regional tax treatment of pareja de hecho, donaciones and inheritance vary and change; always confirm your specific position with a Spanish property lawyer and a gestor or tax adviser familiar with your home country's treatment of Spanish assets.