Guide & traps
The short version of what married couples in Germany should know about tax classes, small jobs and the year-end bill.
1. Tax classes only change the timing
A married couple files one joint return with the splitting tariff. The final tax for the year does not depend on the tax classes. The classes only decide how much the employers withhold each month.
| Pair | Good for | Watch out |
|---|---|---|
| IV / IV | Similar salaries | With very different salaries, too much is withheld: refund later. |
| III / V | Very different salaries, highest monthly cash | Often too little is withheld: back-payment, then quarterly prepayments. Return is mandatory. |
| IV / IV + factor | Withholding close to the real tax, fair split between payslips | Apply each year with your expected salaries (Form "Antrag auf Steuerklassenwechsel"). Return is mandatory. |
2. The minijob and midijob trap
- A minijob (up to €556 a month in 2025, €603 in 2026) is taxed flat by the employer. The wage stays out of your joint return and only 3.6 % goes to the pension (you can opt out).
- One euro more and it is a midijob: social contributions start (low at first, rising to the full ~21 % at €2,000), and the whole wage now counts in your joint return, taxed at your shared rate.
- Next to a well-paid partner, that shared rate is often 30–42 %. So a job just above the limit can leave the family less than a minijob. The salary chart on the calculator shows where the gap closes for you.
- Class V makes it look worse on the payslip than it is. The payslip is not the truth; the joint return is. Look at "what the job adds to the family".
3. Back-payments and prepayments
- III / V, side income without withholding, and tax-free benefits are the usual reasons for a back-payment.
- From €400 a year (and €100 a quarter) the tax office sets quarterly prepayments (§ 37 EStG) for the current and next year. Missing them leads to dunning fees and, in the end, enforcement.
- The factor method, or registering an allowance (Freibetrag) for high work costs, keeps withholding close to the real tax.
4. Tax-free benefits raise your rate
Parental allowance, unemployment benefit, sick pay and maternity pay are tax-free. But they are added when finding your tax rate (Progressionsvorbehalt, § 32b EStG). The higher rate then applies to your other income. In a year with parental leave this easily means a back-payment of several hundred euros. Above €410 of such benefits, a return is mandatory.
5. Plan class changes around a baby or a job loss
- Parental allowance is 65–100 % of a flat net pay. That net uses the tax class held in most of the 12 months before the birth. For the partner taking leave, class III gives more. In practice, switch about seven months before maternity protection starts.
- Unemployment benefit uses the class held on 1 January. A change during the year counts only if it fits the ratio of your salaries, or if it lowers the benefit.
- No parental allowance if your joint taxable income in the year before the birth is above €175,000.
6. Health insurance
- A spouse without own insurance is insured free through a partner in statutory insurance, while own income stays at or below €565 a month in 2026 (€535 in 2025), or a minijob.
- With a privately insured partner earning well, that free family insurance is not available. Then a small job that brings insurance is worth more.
- Statutory contributions are fully deductible (health minus 4 %). Only the basic-cover part of a private premium is deductible.
7. Easy deductions people miss
- Commute: €0.30 per km for the first 20 km and €0.38 after (2025); €0.38 from the first km (2026). One way, per day at the workplace.
- Home office: €6 a day, up to 210 days (€1,260).
- Childcare: 80 % of costs, up to €4,800 per child under 14.
- Household services and craftsmen: 20 % of the labour cost straight off the tax (up to €4,000 and €1,200).
- Supporting parents or other relatives: up to the basic allowance per person, less in low-cost countries.
- Work equipment, training, union fees, job applications, the €16 account fee. All only count once above the €1,230 flat amount.
How the calculator works
- Withholding runs the official BMF wage-tax pseudo-code (Programmablaufplan) for 2025 and 2026, month by month. The 2026 code is checked to the cent against the BMF test interface.
- The joint return follows § 32a (tariff), § 32b (Progressionsvorbehalt), § 10 (pension, health and other provisions), § 33 (own share of medical costs, step by step), § 33a, § 33b, § 35a, the Kindergeld check (§ 31) and soli with its phase-in.
- Each partner's share of the joint tax follows § 270 AO: the ratio of the taxes each would pay alone.
- Social contributions use the year's ceilings and rates, the midijob formula, the care-insurance child rules, Saxony, and the ceiling for one-off pay.
Not covered
- Capital income (taxed separately at 25 %), Riester, company pensions and tax-free employer perks.
- Separate assessment, unmarried couples, more than one job per person, class changes during the year.
- Special church-tax rules (Kirchgeld, caps), and the reduced midijob base in the wage-tax Vorsorgepauschale.
An estimate, not tax advice. For your filing, check with ELSTER or a tax adviser.