Living together in the Netherlands creates almost no legal relationship between you.
There is no common-law marriage here, and no number of years at the same address will produce one.
What cohabitation does create is a set of consequences you did not choose: tax treatment, benefit calculations and pension conditions that switch on the moment you share an address.
The rights you might actually want - inheritance, maintenance, a claim on the home - have to be bought and written down.
What Registering Together Changes On Its Own
You must register your address in the Basisregistratie Personen within five days of moving, and in Amsterdam that means ID plus a rental contract or the owner’s written permission for the address.
That registration is what triggers everything else.
For income tax you become fiscal partners automatically once you share a registered address and one further condition applies: a notarial cohabitation agreement, a child together, joint ownership of the home you live in, naming each other as pension partners, or one of you having a minor child at the address.
Fiscal partnership lets you divide certain deductions between you, which usually helps, and it makes you jointly visible to the tax office, which sometimes does not.
For allowances the effect is blunter.
Huurtoeslag, zorgtoeslag and kindgebonden budget are calculated on combined household income once you are toeslagpartners, so a partner moving in can reduce or end an allowance you were receiving.
Basic health insurance stays individual and is unaffected.
What A Notarial Agreement Buys
A samenlevingscontract is a notarial deed, not a private document, and a Dutch notary must execute it.
Expect roughly €400 to €1,000 depending on the office and how much you are arranging, with online notary services at the bottom of that range and traditional Amsterdam practices at the top.
Three things make it worth the money rather than a nice-to-have.
The first is pensions: most Dutch pension funds will not pay a partner pension to a surviving cohabitant without a notarial agreement and a separate registration of the partner with the fund, and the fund’s own rules decide, not the law.
The second is inheritance tax.
A surviving cohabitant can claim the same exemption as a married partner - €828,035 in 2026 - but only after a notarial agreement containing a mutual care obligation plus six months at the same address, or five years of shared household without one.
Fall outside that and the exemption drops to €2,769, with tax at 30 per cent on the first €158,669 and 40 per cent above it.
The third is proof.
If one of you paid the deposit, funded the kitchen or covered the mortgage while the other’s name was on the deed, the agreement is what records it before anyone has a reason to argue.
The Gaps The Agreement Does Not Close
A cohabitation agreement does not make you heirs.
Without a will, a surviving cohabiting partner inherits nothing at all - the estate goes to the deceased’s children, or failing that to parents and siblings - so a will and the agreement are a pair, not alternatives.
It also creates no maintenance obligation after a break-up, however long you lived together and whatever either of you gave up to do it.
If one partner reduces their hours to raise a child, nothing in Dutch law compensates that on separation, and only a written agreement can.
Tenancy is one place the law does help.
A partner who has run a genuine joint household at a rented address for at least two years can ask the landlord, and failing that the court, to be recognised as a co-tenant, which protects them if the named tenant leaves or dies.
Parenthood is another.
An unmarried father has no legal tie to the child until he acknowledges it at the municipality, and since 1 January 2023 that acknowledgement also grants joint custody automatically.
For a child acknowledged before that date, custody had to be applied for separately, so if your family predates the change it is worth confirming that both parents are actually registered as having it.
When To Get Advice
A notary is the right first call for the agreement itself, for a will, and for anything involving buying property together.
A family lawyer is the right call once there is a dispute, a child, or a cross-border element such as assets or a former marriage in another country.
Free first-line advice is available from Het Juridisch Loket and from the Amsterdam Buurtteams, and subsidised representation is possible below an annual income of €30,000 for a single person or €42,400 for a couple.
That is worth checking before you assume a lawyer is out of reach.
Frequently Asked Questions
Registration, money and what happens if it ends cover almost everything couples ask.
Is there common-law marriage in the Netherlands?
No. Living together for any length of time creates no marital rights, no maintenance duty and no inheritance claim.
Everything you want has to be arranged deliberately.
What does a cohabitation agreement cost?
Roughly €400 to €1,000 through a Dutch notary, with online services cheapest and full-service Amsterdam offices at the top of the range.
It must be a notarial deed to satisfy pension funds and the inheritance-tax exemption.
Do I inherit from my partner if we are not married?
Not without a will - a cohabiting partner has no statutory claim on the estate.
With a will and a qualifying notarial agreement, the partner exemption for inheritance tax is €828,035 in 2026, the same figure married couples get.
Will my partner get my pension if I die?
Only if your pension fund’s rules allow it, which almost always means a notarial cohabitation agreement plus registering your partner with the fund.
Check the fund directly, because the conditions differ between schemes and none of them apply automatically.
Does moving in together affect our tax and benefits?
Yes, immediately and in ways people do not expect.
Sharing a registered address plus one further condition makes you fiscal partners for income tax, and it makes you toeslagpartners, so rent and healthcare allowances are recalculated on joint income.
Basic health insurance premiums are unaffected.
What happens to the flat if we split up?
Whoever is named on the lease or deed keeps it, unless you agreed otherwise in writing.
A partner who has shared a rented home for two years or more can apply for co-tenant status, which is the main protection available to the unnamed partner.
Do we need a notary or can we write it ourselves?
A private agreement is valid between the two of you but will not satisfy pension funds or qualify you for the inheritance-tax partner exemption.
For those, only a notarial deed counts.
