Joint vs. Separate Assessment

If you are married or in a registered partnership, you may choose how to be assessed for income tax: jointly or separately. That is not a formality but real money. Joint assessment triggers income splitting - your combined taxable income is halved, the tax calculated for the half and then doubled. The more your incomes differ, the bigger the splitting advantage.

The check does the calculation you would otherwise have to run twice by hand. You enter the taxable income of Person A and Person B, and the tool computes both routes: joint assessment with splitting, and separate assessment where each person is taxed individually under the basic rate. At the end you get the recommendation with the concrete euro difference per year.

It uses the official income tax tariff under Section 32a. For 2026 the basic allowance is 12,348 euros per person - no income tax is due up to that. The splitting advantage arises exactly where one partner earns a lot and the other little or nothing: the high income is then spread across both on paper and the progression is dampened. If both earn roughly the same, the advantage is small or zero.

Besides income tax, the check also factors in the solidarity surcharge, because its exemption thresholds differ between separate and joint assessment. Both results are cleanly broken down into income tax, surcharge and total so you can follow where the difference comes from.

Worth knowing: in the vast majority of cases joint assessment is cheaper or equal. Separate assessment only pays off in special situations - for example if one partner receives wage-replacement benefits subject to the progression proviso, has high extraordinary expenses or claims losses. The check shows you at once whether yours is such a special case.

You can calculate for 2026 or 2027. For 2027 the tariff values are still preliminary because the final figures from the Federal Ministry of Finance are not yet set - the check flags this. Everything runs data-frugally; your incomes never leave your device. This is not tax advice but an honest decision aid.