Applying for a tax number and VAT ID in Germany: all the numbers at a glance

Four numbers compared

The names are similar, the purposes are not. The following overview shows which number is for what and where you need it.

Tax ID: the personal number you already have

Everyone registered in Germany has a tax identification number (steuerliche Identifikationsnummer). It is assigned automatically with your first registered address, never changes and appears on your wage tax certificate, on income tax assessments and in the letter the BZSt sends after you register. If you are new to Germany, you receive it by post a few weeks after registering with the residents’ registration office.

If you have lost it, you can request it again via the input form on the BZSt website; for data protection reasons it is only sent by post. For your self-employment you need the tax ID in the tax registration questionnaire (Fragebogen zur steuerlichen Erfassung) and in your income tax return – it does not belong on invoices or websites.

Applying for a tax number: how it works

There is no separate “tax number” application. You apply for it by submitting the tax registration questionnaire via Mein ELSTER – within one month of starting your activity, whether you are a freelancer (Freiberufler) or trade business (Gewerbe). The tax office checks the details, may ask questions and sends the tax number by letter.

On letters from the tax office it usually appears in the state format, e.g. 12/345/67890. In ELSTER and bookkeeping software this becomes the nationwide 13-digit format, which also contains the federal tax office number. Both refer to the same number. The tax number is tied to the tax office: if you move into another tax office’s district, you get a new one. If the tax office assigns different numbers for income tax and VAT, use the business-related one for VAT and on invoices.

• Create an ELSTER account (up to two weeks with a certificate file, immediately with the online ID function).
• Fill in and send the tax registration questionnaire; save the transmission log.
• Answer the tax office’s questions quickly – they are the most common reason for delays.
• Receive the tax number by post, usually after two to six weeks.
• Enter the tax number in your invoice template and bookkeeping.

Applying for a VAT ID: in the questionnaire or online at the BZSt

You need the VAT identification number (Umsatzsteuer-Identifikationsnummer) as soon as you deal with businesses in other EU countries: when you provide services to them and the reverse charge procedure applies, when you supply goods to them or when you buy services from elsewhere in the EU, such as advertising, cloud hosting or software subscriptions. If you have EU clients, you also report these sales in the EC sales list (Zusammenfassende Meldung).

New founders tick the application in the tax registration questionnaire. The tax office forwards it to the BZSt, which sends the number by post after the tax number. If you already have a tax number, you apply for the VAT ID online via the form on the BZSt website; you need your tax number and responsible tax office for this. Assignment is free of charge and usually takes one to two weeks.

Beware of letters from private companies asking for money to “register” or “publish” your VAT ID: they have nothing to do with the BZSt. Small businesses (Kleinunternehmer) can also get a VAT ID; they still do not charge VAT.

Business identification number (W-IdNr.): new, but nothing to do

The W-IdNr. (Wirtschafts-Identifikationsnummer) is a nationwide identifier for everyone engaged in economic activity. It consists of “DE”, nine digits and a five-digit distinguishing suffix for the individual activity, for example DE123456789-00001. If you already had a VAT ID, you get the same nine digits; if you apply for the VAT ID later, you receive a VAT ID with the digits of your W-IdNr.

You do not need to apply for it. The BZSt has been assigning it gradually since November 2024 and notifies you via your ELSTER account; for businesses with a VAT ID issued by the end of November 2024 a public announcement applies. Distinguishing suffixes for several activities have been assigned since 2026. On invoices the W-IdNr. replaces neither the tax number nor the VAT ID, and stating it in tax returns is not mandatory until the end of 2026.

How long does each step take?

Waiting times add up if you start late. If you only submit the questionnaire after your first job, you wait correspondingly longer for your first complete invoice.

Which number goes on the invoice?

Under § 14 Abs. 4 Nr. 2 UStG an invoice must contain the tax number or the VAT ID of the supplier. Many self-employed people prefer to use the VAT ID, because the tax number is linked to your tax office and data that third parties do not need. All other mandatory details are in the guide writing invoices.

Writing invoices before you have a tax number

You may work before the tax number arrives. But an invoice without a tax number or VAT ID is incomplete: your client cannot deduct input VAT from it and can ask for a corrected invoice. A note “tax number applied for” does not replace the mandatory detail, and the tax ID is not an acceptable substitute.

Example: graphic designer Ana starts on 2 March, sends the questionnaire on 5 March and completes a project for €3,000 net plus €570 VAT on 20 March. The tax number arrives on 14 April. Ana issues the invoice on 14 April, with March as the service period. With cash-basis VAT (Ist-Versteuerung) she reports the €570 in the month the client pays. With accrual-basis VAT (Soll-Versteuerung) the VAT already arises in March, because she performed the service in March – it belongs in the VAT return for March, even if the invoice is only written in April.

• Best: document the service and only issue the invoice once you have the tax number. You must issue invoices to businesses within six months – that is usually enough.
• If the client insists: issue the invoice without a tax number and correct it once you receive it. Because the other details are correct, under current case law the correction can take effect retroactively from the original date.
• Ask the tax office: if the tax number has already been assigned but not yet delivered, some tax offices give it out by phone after checking your identity.
• You can bill small amounts up to €250 gross without a tax number as a small-amount invoice – this also applies to small businesses (Kleinunternehmer).

Tax number and VAT ID with Kontelio

In Kontelio you enter your tax number and VAT ID under “Tax registrations”, each with a validity period. Kontelio automatically prints the correct number on every invoice and e-invoice, derives from the client’s country and VAT ID whether reverse charge applies, warns if the client’s VAT ID is missing and uses the numbers in the VAT return, the annual VAT return and the EC sales list. After a move, old invoices keep the number that was valid at the time. More about Kontelio’s invoicing software.

Frequently asked questions