Tax Partner (Fiscaal Partner)
Who qualifies as your tax partner (fiscaal partner) in the Netherlands, and how it affects your tax return, deductions, and credits.
Key Takeaways
- A tax partner (fiscaal partner) is someone with whom you can jointly allocate certain income and deductions on your Dutch tax return.
- You are automatically a tax partner if you are married or in a registered partnership (geregistreerd partnerschap).
- Unmarried cohabitants can also be tax partners if they meet specific conditions (such as being registered at the same address and having a joint mortgage or child).
- Having a tax partner allows you to optimize your tax return by distributing Box 2 and Box 3 income, and certain deductions, between partners.
- You cannot choose to be a tax partner for part of the year — you either are or you are not for the entire tax year (with some exceptions for the year you start or end the partnership).
Who Is Your Tax Partner?
Automatic Tax Partners
You are automatically considered tax partners if:
- You are married
- You are in a registered partnership (geregistreerd partnerschap)
No further conditions need to be met. The moment you marry or register your partnership, you become fiscal partners for tax purposes.
Conditional Tax Partners (Unmarried Cohabitants)
If you live together but are not married or in a registered partnership, you can qualify as tax partners if you are both registered at the same address in the BRP (Basisregistratie Personen) and at least one of the following applies:
- You have a notarial cohabitation agreement (samenlevingsovereenkomst)
- You have a joint child
- One of you has recognized the other's child
- You are each other's pension partner under a pension scheme
- You jointly own the home you live in
- One of you is listed as a partner on the other's mortgage for the home
Good to know
Simply living at the same address is not enough to become tax partners. You need to meet at least one of the additional conditions listed above. Conversely, if you are married, you are always tax partners — even if you live at different addresses.
Who Cannot Be Your Tax Partner?
- A housemate or flatmate (unless you meet the conditions above)
- A parent or child (unless additional conditions are met, which is rare)
- Someone you are separated from (if the divorce is pending, specific rules apply)
- You can only have one tax partner at a time
What Can Tax Partners Allocate?
Having a tax partner gives you the ability to distribute certain income and deductions between the two of you in any ratio you choose. This is called "gezamenlijke inkomensbestanddelen" (joint income components).
Items You Can Allocate
| Item | Box | Allocation Allowed |
|---|---|---|
| Income from substantial interest (aanmerkelijk belang) | Box 2 | Yes — any ratio |
| Savings and investments (vermogen) | Box 3 | Yes — any ratio |
| Owner-occupied home deduction (eigenwoningforfait minus mortgage interest) | Box 1 | Yes — any ratio |
| Qualifying maintenance payments (alimentatie) | Box 1 | Yes — any ratio |
| Qualifying charitable donations (giften) | Box 1 | Yes — any ratio |
| Qualifying medical expenses (specifieke zorgkosten) | Box 1 | Yes — any ratio |
| Education expenses (studiekosten) | Box 1 | Yes — any ratio |
Items You Cannot Allocate
| Item | Box | Rule |
|---|---|---|
| Employment income (salary) | Box 1 | Always taxed with the person who earns it |
| Business profit (self-employment) | Box 1 | Always taxed with the business owner |
| Pension income | Box 1 | Always taxed with the recipient |
| Social benefits (WW, WIA, AOW) | Box 1 | Always taxed with the recipient |
Warning
You can only allocate the joint income components — not your salary or business income. Many people mistakenly think they can split their employment income with a lower-earning partner. This is not possible.
How to Optimize Your Tax Return
The main benefit of being tax partners is the ability to allocate deductions and certain income to whichever partner benefits most. Here are the key strategies:
Strategy 1: Allocate Deductions to the Higher Earner
Deductions like mortgage interest, charitable donations, and medical expenses reduce your Box 1 taxable income. If one partner earns €80,000 (49.50% bracket) and the other earns €30,000 (36.97% bracket), allocating all deductions to the higher earner saves more tax.
Example: €15,000 in mortgage interest deduction
| Allocation | Tax Saved |
|---|---|
| 100% to partner earning €80,000 | €15,000 × 36.97% = €5,546* |
| 100% to partner earning €30,000 | €15,000 × 36.97% = €5,546* |
| Optimal allocation | Depends on credit phase-outs |
The mortgage interest deduction rate is capped at the first bracket rate (36.97%) regardless of your actual bracket. However, allocating it to the higher earner can still be beneficial because it affects credit phase-outs.
Strategy 2: Allocate Box 3 Assets Optimally
Box 3 taxes your savings and investments based on a deemed return. The tax rate and deemed return increase with higher asset levels. By distributing assets between partners, you can potentially keep both partners in lower Box 3 brackets.
Example: €200,000 in savings and investments
| Allocation | Result |
|---|---|
| 100% to one partner | Higher deemed return on the full amount |
| 50/50 split | Each partner gets their own tax-free threshold (€59,357 each), potentially lower total tax |
Tip
The optimal allocation is not always obvious and depends on both partners' complete financial picture. The Belastingdienst's online filing tool lets you try different ratios and instantly see the effect on your combined tax. Use this feature — do not guess.
Strategy 3: Use the Non-Earning Partner's Tax Credit
If one partner does not work or earns very little, they still have a general tax credit. While the transferable portion has been largely phased out, filing a joint return ensures any remaining transferability is applied.
Tax Partner and the General Tax Credit
The general tax credit has a special relationship with tax partners. A partner who has no or low income cannot fully use their general tax credit (you need to owe tax for a credit to be useful). A limited portion of the unused credit can be paid out to the non-earning partner.
This transferable amount (uitbetaling algemene heffingskorting) has been gradually reduced and is very small for partners born after 1963. For the exact current amount, check the Belastingdienst website.
When Does the Partnership Start and End?
Starting Mid-Year
If you get married or start a registered partnership during the year, you are considered tax partners for the entire year. This is beneficial because you can optimize your complete annual income and deductions.
Exception: if you meet the conditions for being tax partners only partway through the year (e.g., you move in together in June), you can choose to be tax partners for the entire year, but you are not required to.
Ending Mid-Year
If you divorce during the year, the tax partnership ends on the date the divorce is finalized. Special rules apply for the transition year.
If one partner dies during the year, you are considered tax partners for the entire year. You can still file a joint return and allocate income components optimally.
Tax Partner Impact on Specific Deductions
Mortgage Interest
The mortgage interest deduction on your primary residence (eigenwoningaftrek) is a joint income component. You can allocate it freely between partners, regardless of who actually pays the mortgage or whose name is on the mortgage deed.
Box 3 Threshold
Each tax partner has their own Box 3 tax-free threshold (heffingsvrij vermogen) of €59,357 in 2026. Together, you have €118,714 of tax-free savings and investments. This is one of the most straightforward benefits of being tax partners.
Toeslagen (Allowances)
Being tax partners also affects your eligibility for government allowances (toeslagen) like:
- Zorgtoeslag (healthcare allowance)
- Huurtoeslag (rent allowance)
- Kinderopvangtoeslag (childcare allowance)
- Kindgebonden budget (child-related budget)
For these allowances, the combined income of both tax partners is used to determine eligibility. This means that becoming tax partners can cause you to lose allowances if your combined income is too high.
Warning
Becoming tax partners is not always beneficial. If one partner receives toeslagen, the combined income test may disqualify them. Carefully consider the full financial picture — including allowances — before choosing to register as tax partners (for unmarried couples who have a choice).
Tax Partner for Expats
As an expat, there are a few special considerations:
- If your partner lives abroad, they may still be your tax partner if you are married or in a registered partnership. However, their worldwide income is taken into account for the income test.
- If you have the 30% ruling, your partner can still qualify as a tax partner under normal rules.
- Partial non-resident taxpayers (partieel buitenlands belastingplichtigen) under the 30% ruling: your partner's foreign income may affect Box 3 calculations.
- If you arrive mid-year, you can choose whether to be tax partners for the entire year or only for the period of residency.
Common Mistakes
- Assuming cohabitation automatically makes you tax partners — You need to meet at least one additional condition beyond living at the same address.
- Not optimizing the allocation of joint income components — Many couples simply split everything 50/50 without checking if a different ratio would save tax.
- Forgetting the impact on toeslagen — Becoming tax partners can reduce or eliminate government allowances.
- Not filing a tax return for the non-earning partner — If your partner has no income, they may still be entitled to a tax credit payout. But only if they file.
- Allocating employment income between partners — Salary cannot be allocated. Only the specific joint income components listed above can be distributed.
What to Read Next
- General Tax Credit (Algemene Heffingskorting) — How the general tax credit works and transfers between partners
- Mortgage Interest Deduction — Deducting mortgage interest as a tax partner
- Box 3: Savings and Investments — How Box 3 works and the tax-free threshold per partner