Germany: our calculator now computes tax class III for a married couple with one income

What changed

This note records an extension and a correction of our calculator, not a change in the law. Since 17 October 2026, our calculator has computed German income tax as the official withholding algorithm of the Federal Ministry of Finance does, but only in tax class I, that of a single person. Our tax comparison tool, which offers a married household, therefore computed a German couple as a single person, without saying so.

Since 18 October 2026, a married household is computed in tax class III. Under § 38b of the Income Tax Act (EStG), a married couple can jointly apply for class III for the spouse who works, the other spouse moving to class V, including when that spouse has no wage; without the application, both spouses are in class IV and each is taxed like a single person. In class III, § 39b has the wage tax computed with the splitting procedure of § 32a, subsection 5: twice the tax due on half the taxable income. The allowances remain those of class I: the EUR 1,230 employee allowance, the EUR 36 special-expenses allowance and the allowance for social contributions. The solidarity surcharge is only due above EUR 40,700 of tax instead of EUR 20,350, under § 3 of the Solidarity Surcharge Act.

The Germany page of the calculator now offers this choice of household: “Single (tax class I)” or “Married, one income (tax class III)”. Our computation reproduces the official algorithm without a single difference over 115,018 salaries, the tax to the euro and the solidarity surcharge to the cent. Still outside the computation are classes IV/IV and III/V for couples with two wages, the joint annual assessment, which sets the final tax, and child allowances. In classes IV/IV, each spouse is taxed at source like a single person: the page’s class I computation then applies to each of the two salaries.

Effective date

Splitting in class III is not new. The amounts applied are those of 2026: the § 32a scale applicable to 2026, the EUR 40,700 solidarity-surcharge threshold and the 2026 withholding algorithm. Our calculator has applied class III since 18 October 2026, on the Germany page in both languages and in the tax comparison tool.

Worked example

Figures produced by our net salary calculator, married couple where only one spouse has a wage, no children, statutory health insurance at the average supplementary contribution rate, a 1.8% long-term care share, before the correction (class I) and after (class III). Tax includes the solidarity surcharge; social contributions are unchanged.

The difference is the tax saved, contributions being unchanged. At EUR 30,000 gross, the couple’s taxable income stays below the doubled tax-free threshold of class III, and the tax is nil. At EUR 150,000, the solidarity surcharge, EUR 2,440.29 in class I, disappears in class III: the tax of EUR 33,282.00 stays below the EUR 40,700 threshold.