Married couples can choose between two forms of income tax assessment. Whether a joint tax return pays off depends above all on how income is distributed between the partners. This comparison shows the rules, the choice and the typical cases.
Short answer: Spouses are assessed jointly under section 26 EStG (in German) if both choose this or make no choice. Joint assessment usually pays off when incomes differ strongly. With similar incomes the advantage is often small. A binding answer requires a calculation for the year in question.
The most important points at a glance
- Married couples can choose between separate and joint assessment if they meet the requirements.
- The choice is made together in the tax return. If no choice is made, joint assessment applies.
- For jointly assessed spouses, child allowances double if the child stands in a parent-child relationship to both.
- Tax classes affect the monthly net pay, not the final tax.
- For a concrete decision, a comparison calculation for the year in question is worthwhile.
Which requirements apply to joint assessment?
Under section 26(1) EStG (in German), spouses can choose between separate and joint assessment if both are unlimitedly liable to income tax and do not live permanently apart. The requirements must exist at the start of the assessment period or arise during the year.
The choice is made by stating it in the tax return. If both choose joint assessment, it is carried out. If the right of choice is not exercised or not validly exercised, joint assessment applies automatically under section 26(3) EStG. Anyone who does not expressly request separate assessment therefore ends up in joint assessment.
How does joint assessment affect the tax?
With joint assessment, the incomes of both partners are added and taxed together. The splitting method then halves the combined income on paper. This explains why unevenly distributed incomes often bring the largest advantage. The exact calculation and the tax brackets are checked by the tax office or a tax program.
Assumption: Partner A earns 60,000 euros per year and partner B has no income. Under joint assessment the income is divided on paper between both, which often lowers the tax burden noticeably. With two equally high incomes this effect is usually much smaller, because the distribution hardly changes.
When does a joint tax return pay off?
A comparison shows that the pattern of incomes makes the difference. The table below sorts the typical cases. It does not replace a calculation, but it helps you place your situation before an appointment.
| Pattern | Typical effect | What to check |
|---|---|---|
| One partner earns, the other does not | Joint assessment often advantageous | All income and deductions of both partners |
| Different incomes | Advantage depends on the gap | Comparison calculation for the year in question |
| Similar incomes | Advantage usually small | Whether deductions close the gap |
| Living apart | Assessment depends on the requirements | Whether the requirements actually apply |
The tax advantage is only part of the decision. Joint assessment also matters for child benefit and child allowances, because the allowances double for jointly assessed spouses if the child stands in a parent-child relationship to both. The rule is in section 32(6) EStG (in German).
What role do the tax classes play?
Tax classes determine how much wage tax is deducted each month. Under section 38b EStG (in German), spouses can be assigned to the combinations III and V or IV and IV, and to class IV with a factor. The class does not change the final tax, however. Anyone who paid too much receives the amount back in the assessment, and anyone who paid too little has to pay the difference.
Especially with very unequal incomes, the choice of classes makes a noticeable difference to the monthly budget. The net pay in the current year is therefore not the best yardstick, rather the sum after the assessment. If you want to change classes, clarify this with the tax office beforehand.
How do you approach the decision?
A structured comparison needs the income of both partners, the deductions and the children. You can run the calculation with a tax program or with the tax calculator of the Federal Ministry of Finance. For the decision, the figures of one specific year count, not general rules of thumb.
Which information does a comparison calculation need?
A reliable comparison starts with complete information. If an income or a deduction is missing, the result shifts, and the comparison looks more certain than it is. Collect the documents for both partners before you calculate. This matters especially if salary, a side job or self-employment changed during the year.
- Gross income from employment with the wage tax certificates of both partners
- Income from self-employment, letting or capital gains with the corresponding records
- Work-related expenses, special expenses and extraordinary burdens, where they arose
- Details on children, childcare costs and the periods in which they count
- Details on wage tax classes and advance payments already made
It is also important whether separate assessment starts from the same basis for both partners. Deductions that belong to only one person work differently under separate assessment than in the joint calculation. Anyone who overlooks this point compares two calculations with different bases. A tax program or advice helps you record the information cleanly.
Frequently asked questions
Must married couples be assessed jointly?
No, marriage does not require joint assessment. The choice is expressly possible, and anyone who wants separate assessment must request it. Without a choice, however, joint assessment applies under section 26(3) EStG (in German). It is therefore worth deciding the question deliberately before filing the return.
Can the choice still be changed later?
The choice applies to the respective assessment period and is exercised in the tax return. Whether and how a later change is possible is decided by the tax office in the individual case on the basis of the rules. The office names the deadline and the form.
What happens if the couple separates during the year?
Spouses living permanently apart do not fall under joint assessment if the requirements are not met. A separation during the current year therefore raises its own questions. Clarify the effects with the tax office or a tax adviser before the return is filed.
Is the splitting advantage linked to the current reform?
Whether the spousal splitting will be changed in future is debated politically. The background and the state of the debate are described in Spousal splitting: why its abolition is debated (in German). For the current return, the law of the respective year applies.
What you should do now
- Collect the income, deductions and details about children for both partners.
- Calculate separate and joint assessment for the year in question.
- Decide together and record the result in writing.
- Check the tax classes if incomes change during the year.
Related articles
- Family, Partnership and Money: The overview for young adults
- Spousal splitting: why its abolition is debated
- Separation of property or accrued gains
- Family planning and finances: what couples should settle
Sources: Section 26 EStG, assessment of spouses (German), legal text, Section 32 EStG, child allowances (German), legal text, Section 38b EStG, wage tax classes (German), legal text.
Last updated: November 2026. This guide is general information, not individual advice.
