German tax ID and tax classes explained

In Germany, your employer withholds tax based on your 11-digit tax ID and a tax class from I to VI, and the wrong class or a box ticked for "Catholic" can cost you real money.

The short version

The Steuer-ID arrives by mail after you register your address. It's free, and if it hasn't come within three months, you can ask for it [1].
Your tax class (Steuerklasse) sets how much your employer withholds each month. Singles are in class I, single parents in II, married couples in IV/IV, III/V or IV with a factor [2][3].
Tax classes III and V aren't going away yet. A 2024 plan to scrap them from 2030 was dropped from the final law [4].
If you file your own German return, the 2025 return is due July 31, 2026, or March 1, 2027 with a tax adviser [5].
Church tax in Berlin is 9% of your income tax if you're a member of a church that collects it. Leaving costs €30 (about USD 33) at the local court [6][7].

USD conversions in this guide use the Federal Reserve H.10 rate of October 30, 2026 (USD 1.1163 per euro).

The Steuer-ID: your German tax number for life

The steuerliche Identifikationsnummer (Steuer-ID or IdNr.) is an 11-digit number that stays with you for life, a bit like your Social Security number but only for taxes. You don't apply for it. When you first register an address at a Berlin Bürgeramt, the office forwards your data to the Federal Central Tax Office (Bundeszentralamt für Steuern, BZSt), which mails the number to your registered address [1].

What to know:

It costs nothing [1].
If it hasn't arrived within three months of your first registration in Germany, you can send your details to the BZSt [1].
You can request it again online or in writing if you lose it. It comes by mail, never by email or phone, for data protection reasons [2]. In urgent cases, your local tax office (Finanzamt) can give it to you in person if you show ID [1].
Give it to your employer right away. Without it, payroll can't pull your tax data and may withhold at the highest rate.

Don't mix it up with the Steuernummer, the separate tax number your Finanzamt assigns once you file a return or start freelancing.

The six tax classes

Germany's wage tax system is based on Lohnsteuerklassen. Your employer pulls your class electronically from the tax office's database (called ELStAM), along with your church tax status and child allowances [2]. You can check what's stored by logging into ELSTER, the tax office's online portal [2].

Class	Who it's for
I	Single, divorced or permanently separated people. Also married people whose spouse lives abroad [2].
II	Single parents who qualify for the single-parent relief (Entlastungsbetrag) [2]
III	The higher earner in a married couple who chose III/V [2]
IV	Married people living in Germany, the default combination IV/IV [2]
V	The lower earner in a III/V couple [2]
VI	A second or further job held at the same time as your main job [2]

That class I line matters for Americans. If you move to Berlin and your spouse stays back home in the States for a while, you'll generally be in class I until they move over. Once you're both registered in Germany, you can be put on a married class.

Married couples: IV/IV, III/V or the factor method

When you marry, or register as a married couple, the system starts you in IV/IV [2]. Each spouse is taxed roughly as if single, and the benefit of joint filing (Ehegattensplitting) comes later with the annual return.

You can change that together:

Combination	Best for	The catch
IV/IV	Couples who earn about the same	Little extra cash during the year
III/V	One high earner, one low earner	The class V paycheck shrinks a lot, and you must file a return [2]
IV with factor (Faktorverfahren)	Couples with uneven incomes who want withholding closer to what they'll actually owe	You must file a return [2]

The factor method applies the benefit of joint filing more precisely during the year [3]. Couples apply jointly to their Finanzamt, and the deadline for a change is November 30 of that year [3]. You can usually change only once a year, with exceptions for things like job loss, returning to work after parental leave or separation [3].

One more heads-up from Berlin's family portal: net pay can affect parental benefits (Elterngeld), unemployment pay and sick pay. Check with the benefit office before switching classes if a baby or a job change is coming [3].

Is III/V being abolished?

You may have read that III and V are disappearing. Here's the fine print. In 2024, the government drafted the Steuerfortentwicklungsgesetz, which would have moved all couples into class IV with the factor method from January 1, 2030. The law was passed, but the final version left out the abolition of classes III and V, so for now nothing changes [4]. We'll update this guide if a new law is adopted. Until then, III/V remains a legal choice.

The annual return (Steuererklärung)

Plenty of employees with one job in class I never have to file a German return, since withholding settles it. Many file anyway because they get money back, for example for work equipment, moving costs or a home office.

You must file if, among other cases [2]:

you're married and on III/V, and both of you earn wages
you use the factor method
you had two jobs at the same time (class VI)
you had a tax allowance stored with your withholding data

Return for	If you file yourself	With a tax adviser or wage tax help association
2025	July 31, 2026 [5]	March 1, 2027 [5]

For 2025, the basic tax-free allowance (Grundfreibetrag) was €12,096, or €24,192 for married couples filing jointly [5]. That's about USD 13,500 and USD 27,000. Most people file online through ELSTER, which is free.

Church tax and leaving the church

When you register your address, the form asks about your religion. If you list a church that collects tax, such as the Protestant (evangelisch) or Roman Catholic church, the Finanzamt adds church tax. In Berlin it's 9% of your income tax, withheld from your paycheck and charged on investment income too [6]. In a mixed couple, only the share linked to the member spouse counts [6].

For Americans, this is the moment to pay attention. Most churches back home don't collect tax, so ticking a box for the denomination you grew up in can surprise you. If you don't want to pay, you have to formally leave (Kirchenaustritt):

Find your local court. In Berlin, you declare it at the Amtsgericht (local court) for your address. Court districts don't always match boroughs [7].
Book a slot. A few courts take online bookings; others use a contact form [7].
Pay €30 in advance (about USD 33) [7].
Bring ID and your Meldebescheinigung, plus your marriage certificate if you want the change on record [7].
Sign in person. You can't leave online; the alternative is a notarized declaration [7].

Church tax stops at the end of the month in which your exit takes effect [6]. Updating your payroll data can take a few weeks [6].

How this fits with your US return

Uncle Sam still expects a federal return every year. For tax year 2026, the foreign earned income exclusion is up to $132,900, and for 2025 it's $130,000 [8]. Since German income tax rates are high, many Americans in Berlin use the foreign tax credit on Form 1116 instead. Your German annual tax assessment (Steuerbescheid) is the key document for that, so keep every copy. How church tax and the solidarity surcharge are treated on a US return is a detail where a US expat tax preparer can check your situation.

Tax season questions come up every spring in our community group for Americans in Germany.

German tax ID and tax classes: Steuer-ID, Steuerklassen and church tax for Americans