Buying a House with Your Partner in Belgium: Cohabitation Contract, Ownership and Tax Benefits

Buying a house with your partner: getting it right in 2025

For many couples, buying a first home together is a milestone moment. At the same time, it raises legal and financial questions: do you need a cohabitation agreement? How do you split ownership and debts? And what are the tax benefits of legal cohabitation?

This guide walks you through the practical and legal aspects so that you can take the step towards homeownership together, without any nasty surprises. With reduced registration duties available in 2025, now is a great time to take the plunge.

The basics: married, legal cohabitants, or de facto cohabitants?

Your legal status determines much of what follows. Let us look at the three situations.

1. Married couples

When you marry, the property automatically falls under the community of property regime. This means:

Both partners are automatically joint owners (unless otherwise agreed).
Assets purchased during the marriage belong to both.
On death, the surviving partner inherits automatically - no complicated paperwork.
Both partners are fiscally linked and can file a joint tax return, which brings tax advantages.

Downside: If you separate, everything has to be legally divided. This can become complicated and costly.

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2. Legal cohabitation

This is the middle-ground option: many of the same benefits as marriage, without the ceremony. Legally almost identical to marriage, but you register it at your local municipality (free of charge) rather than through a church or civil ceremony.

Automatic joint ownership of properties bought after the legal cohabitation declaration
Automatic inheritance rights and tax partnership.

Note: Properties bought before the legal cohabitation declaration are not automatically covered, unless you make a separate arrangement.

3. De facto cohabitation (without a contract)

This is the situation many unmarried couples find themselves in. It offers no legal protection:

The property is in the name of one partner only, unless both are listed as owners.
On death, the other partner does NOT automatically inherit - the property passes to the deceased's parents.
No joint tax return, meaning you miss out on tax benefits.
If the relationship breaks down, everything can become more complicated and more expensive.

This is why a cohabitation agreement is so important.

The cohabitation agreement: why you need one

A cohabitation agreement is a notarial deed in which you set out your arrangements regarding money, property, inheritance and what happens if you split up. It is not legally required, but it is enormously practical.

Benefits of a cohabitation agreement

1. Clarity on ownership

You define how the property is owned:

Both 50/50?
In proportion to each person's contribution (e.g. one of you puts in €80,000, the other €20,000)?
One partner owns 100%, the other has a right of residence?

This prevents misunderstandings and disputes further down the line.

2. Tax partnership

With a legal cohabitation agreement, you automatically become tax partners. This brings immediate benefits :

You file a joint tax return; income and deductions can be split in the most favourable way.
In Belgium, a joint return can allow for a favourable allocation of income between partners - for example through the marital quotient mechanism - reducing the overall tax burden.
Mortgage interest deductions can be allocated in the most advantageous way.

Example: Partner A earns €50,000, Partner B earns €30,000. Together they can restructure their combined taxable income across lower tax brackets - a significant benefit.

But watch out: If you both have a property with a mortgage, consult a tax adviser to work out which allocation of deductions is most beneficial for your specific situation. In some cases, filing jointly may not be the best option.

3. Inheritance and death

Without a cohabitation agreement, the deceased partner's property goes to his or her parents - not to you. With an agreement:

You can include an accretion clause: if one of you dies, all jointly-held assets - including the home - pass to the survivor.
You decide who gets what on death, avoiding any dispute with family members.

4. Protection if the relationship breaks down

You agree in advance:

How will the property be divided or sold?
Who pays what?
Can one partner buy out the other?

This prevents expensive legal battles later on.

Drawbacks of a cohabitation agreement

1. It costs money

A cohabitation agreement costs between €150 and €400 at the notary (depending on complexity), plus potentially €100 to €300 for wills.

2. Tax partnership is not always beneficial

In certain situations (e.g. both partners with a mortgaged property), it can work against you.

3. It is not free, whereas a legal cohabitation declaration is

Registering as legal cohabitants at the municipality is free; a notarial cohabitation agreement involves notary fees.

Splitting ownership: what are your options?

When buying a home with your partner, you can choose from several models:

Model	Advantage	Disadvantage
Equal 50/50 ownership	Simple, feels fair	Does not work well if contributions are unequal
In proportion to contribution (e.g. 60/40)	Fair when one partner brings more savings	More complex administration
One owner, the other with right of residence	One partner has tax protection	May be unfavourable for the other
Joint ownership with reservation	Flexible	Requires good cooperation

In practice: The notarial deed sets out exactly how ownership is divided. If the property is in both names at 50/50, each of you pays registration duties only on your half - but note: only the partner who is a first-time buyer (no prior real estate in their name) qualifies for any reduced rate.

Registration duties in 2025: who benefits?

Reduced registration duty rates available in 2025 represent a real saving. The exact conditions depend on the region.

In the Flemish Region, the rate was cut to 2% (down from 3%) from 1 January 2025 for first-time buyers. In the Walloon Region and the Brussels-Capital Region, the standard rate is 12.5%, but reductions and abatements exist for a buyer's own and sole primary residence. Always check with your notary for the exact rules that apply in your region.

General conditions to qualify for a reduced rate or abatement:

First-time buyer (no prior property in full ownership in their name)
Purchasing as a private individual (not through a company)
Purchasing in full ownership
Must establish domicile in the property within the required timeframe

For couples:

The couple buys together and both are first-time buyers? Both benefit from the reduced rate or abatement.
One partner already owned a property? That partner pays the full rate on their share, while the other benefits from the reduced rate.

The choice of ownership structure therefore has a direct financial impact.

Example (using the Flemish 2% rate):

A couple buys an apartment for €250,000:

Both at 50/50 as first-time buyers: 2 × (€125,000 × 2%) = €5,000 in registration duties
Scenario: Partner A already owned a property and holds 50% (full rate), Partner B is a first-time buyer (reduced rate): (€125,000 × 12%) + (€125,000 × 2%) = €17,500 in registration duties

Difference: €12,500! The ownership split clearly matters financially.

Tax partnership: when does it pay off?

This is the key question. Filing jointly sounds attractive, but it is not always the best move.

It is beneficial when:

Your incomes differ (the greater the gap, the more you can gain by combining them across lower tax brackets).
You only have one property with a mortgage (joint deduction of interest).
You want to pool your savings to optimise tax benefits linked to investment income.

It can be disadvantageous when:

You both own a property with a mortgage - the deduction rules may become less favourable depending on your situation.
One partner has considerably more assets than the other (pooling them may produce an unfavourable tax outcome).
You later separate (dissolving a tax partnership is more complicated).

Advice: Have a tax adviser run the numbers before you sign anything. Checking twice can save you thousands of euros.

Getting a mortgage with your partner: how to speed things up

Two incomes = a stronger borrower profile. Banks look favourably on couples:

Higher combined net income = potentially larger loan
Better risk spread (if one income disappears, the other is still there)
Better debt-to-income ratio (monthly repayments vs. income)

Tips:

Both submit your proof of income (employer statements, pay slips).
Ask explicitly whether your status as legal cohabitants gives you any advantage (sometimes yes, sometimes no).
Sign the same mortgage - two separate loans is more complicated and more expensive.

A loan simulator gives you an immediate picture of how much you can borrow together.

Step-by-step plan: buying a house with your partner

Week 1: Decide whether you want a cohabitation agreement (strongly recommended).
Week 2: Consult a notary about the best ownership structure and your tax situation.
Week 3: Use the loan simulator to work out how much you can borrow.
Week 4: Request quotes from at least two banks (important when your tax situation is combined).
Week 5: Gather all documents (employer statements, pay slips, savings account statements for both of you).
Week 6: Sign the cohabitation agreement at the notary (this can run in parallel with the property purchase).
Week 7+: Start house-hunting; use estate agent comparison for local expertise and a free valuation.

Conclusion: stronger together - but make sure it is all in order

Buying a home with your partner is a wonderful step, but it requires preparation. A cohabitation agreement costs time and money now, but it can save you ten times that if things go wrong later. Add in the reduced registration duties available in 2025, and the savings can be substantial.

Start today: have a notary run through your situation, calculate your joint borrowing capacity with the loan simulator, and find local estate agents who have experience working with couples.

Becoming homeowners together: with the right knowledge and preparation, everything runs smoothly.