Question 1

Do I save tax overall with the right tax class?

Accepted Answer

No. Choosing a tax class does not change your annual tax. For married couples it is finalised through income splitting in the tax return, regardless of whether you had IV/IV or III/V during the year. The class choice only determines how much wage tax is withheld each month — your liquidity. Overpaid tax is refunded, underpaid tax must be paid back.

Question 2

What is the difference between III/V and IV/IV?

Accepted Answer

With IV/IV both partners are taxed like single people — each keeps their full basic allowance. With III/V the higher earner in class III gets the doubled basic allowance and therefore pays much less wage tax monthly; the lower earner in class V pays disproportionately more. On balance III/V often leaves the couple with more monthly net, but a back payment looms. IV/IV is more even and produces fewer surprises.

Question 3

Who benefits from the III/V combination?

Accepted Answer

III/V mainly brings more monthly liquidity when the partners' incomes differ significantly — a rule of thumb is roughly 60:40 or more. The higher earner takes class III, the lower earner class V. With almost equal incomes III/V brings hardly any liquidity advantage and only creates unnecessary back-payment risk. Our calculator shows for your actual figures which combination yields the highest combined net.

Question 4

What is the factor method (IV/IV with factor)?

Accepted Answer

With the factor method both partners stay in class IV, but the tax office additionally enters a factor below 1. This factor ensures the monthly withheld wage tax already roughly matches the expected joint annual tax. The tax burden is thus distributed fairly according to income, there is more monthly net than with plain IV/IV and usually no nasty surprise at year-end. The factor is calculated from your annual gross wages and is valid for two years.

Question 5

Do I have to file a tax return with III/V?

Accepted Answer

Yes. The III/V combination (and likewise the factor method) triggers an obligation to file an income tax return. The reason: because monthly wage tax in this combination can be systematically too low, the tax office wants to check the actual tax at year-end. Expect that a back payment may be due and set money aside for it. With IV/IV without a factor this filing obligation usually does not apply.

Question 6

How often and by when can I change my tax class?

Accepted Answer

Married couples can change their tax class several times a year. The application is filed with the tax office (form for changing the tax class of spouses/civil partners), nowadays usually electronically. A change generally takes effect from the month after the application. Timing matters before wage replacement benefits: for the highest possible parental allowance the switch should be made well before the start of the maternity protection period. Allow several months' lead time here.

Question 7

How does the tax class affect parental allowance?

Accepted Answer

Parental allowance is based on the average net pay of the twelve months before the birth (or before maternity protection). Whoever is in a more favourable tax class during that period and therefore has a higher net also receives more parental allowance. For the parent who will draw the parental allowance, switching to a lower tax class (e.g. III) in good time can pay off. The change must, however, be made early enough to take effect within the assessment period.

Question 8

How accurate is this tax class calculator?

Accepted Answer

The calculator uses the 2026 income tax tariff (§ 32a EStG) and current social insurance rates and computes each combination separately for both partners. It makes flat assumptions: statutory health and pension insurance, a 2.9 percent additional contribution and no individual allowances. For comparing the combinations and the monthly liquidity this is very meaningful. The final annual tax, however, depends on your individual assessment — this calculation is non-binding and does not replace tax advice.

Guide: Tax Class Calculator

Tax Classes 2026: Which Combination Pays Off for Couples?

Tax Class III/V or IV/IV — Which Is Better?

The Factor Method (IV/IV with Factor) Simply Explained

Changing Your Tax Class: How It Works, Deadlines and Tips

Tax Class and Parental Allowance: Why the Right Switch Means Real Money

You might also find useful

Gross-to-Net Salary Calculator

Parental Allowance (Elterngeld) Calculator

Midijob Calculator