On many occasions—such as starting a new job or filing a tax return—you will be asked for your Tax Identification Number (Steuer-Identifikationsnummer) or Tax Number (Steuernummer). But what is the difference between them, where can you find them, and what do you need them for? Here are the key facts.
- The Tax ID remains the same for your entire life.
- The Tax Number can change, e.g., if you move or get married.
- Every child automatically receives a Tax ID, which is important for child benefits and tax allowances.
- For your tax return with Taxfix, the Tax ID is sufficient.
🚀 Your Guide
The Tax ID – your lifelong number
Where can I find my Tax ID?
As soon as you are registered in Germany, you automatically receive your personal 11-digit Tax ID by mail. For newborns, it is often the first letter they receive.
If you have lost the letter, you can find your Tax ID:
📄 On your income tax certificate
📑 On your income tax assessment notice
👉 In the Taxfix app, you must enter your Tax ID so the tax office can assign your tax return.
💡 Can't find your Tax ID? You can request it from the Federal Central Tax Office.
Tax ID for children
Every child automatically receives a Tax Identification Number after birth, which is sent to the parents by mail. It is important for tax benefits such as child benefits or the child allowance. In the tax return, you must enter your child's Tax ID if you want to deduct certain expenses.
Learn more here: Children in the tax return.
If you cannot find your child's Tax ID, you can request it via this form from the Federal Central Tax Office.
Tax ID for deceased persons
If you need the Tax ID of a deceased person, you can request it from the Federal Central Tax Office (BZSt).
You must prove that you are authorized to do so—for example, as an heir or estate administrator. A certificate of inheritance or a power of attorney can serve as proof.
The request is made via the contact form at the Federal Central Tax Office.
What is the Tax ID needed for?
The Tax ID is required in many situations, such as:
📌 For the electronic tax return (e.g., with the Taxfix app)
💼 When starting a job for the correct tax class
👶 For applications for child benefits or pensions
🏛 For tax office matters
What data is linked to the Tax ID?
Your Tax ID is linked to various personal data:
👤 Name (including previous names)
📅 Date and place of birth
🏠 Current and previous addresses
📍 Gender and responsible tax office
👉 This data is stored for up to 20 years after death to clarify tax matters.
Who has access to this data?
⚖ Only the tax office can access your data.
Social security providers or banks receive your Tax ID but have no access to the stored data.
The Tax Number – the flexible number
How do I get my Tax Number?
📬 Your Tax Number is automatically assigned to you by mail when you submit your first tax return.
👉 If you have never filed a tax return, you do not yet have a Tax Number.
Where can I find my Tax Number?
📄 At the top left of your income tax assessment notice
📞 If you have lost the notice: Ask the responsible tax office
When do I get a new Tax Number?
Your Tax Number may change if you:
📍 Move to another federal state
💍 Get married or divorced
🔄 Switch from joint to separate assessment
📈 Start self-employment
👉 If you are self-employed and married, you can even have two Tax Numbers—one for your business and one for your marital status.
What is the Tax Number needed for?
The Tax Number is used for various types of taxes, such as:
💰 Income tax
📊 Value-added tax (VAT)
🏢 Business tax
💡 For the income tax return, the Tax ID is usually sufficient. If you already have a Tax Number, you can provide it additionally—this may speed up processing.
🚀 Fill out the simple question-answer flow - we'll take care of the rest!
Still have questions?
We're here to help! Contact our support team: support@taxfix.de