Finanzamt Dortmund-Unna: the German tax office for Turkish companies

Why does Dortmund-Unna write to you?

Dortmund-Unna is your central tax office. As a rule, Germany has one central tax office for VAT per foreign country; for businesses based in Turkey, that is Finanzamt Dortmund-Unna (§ 1 (1) no. 30 UStZustV). It handles your registration, your German tax number and all VAT matters afterwards.

What applies to construction and installation work in Germany?

The same office for income from construction work: for construction firms based abroad, the VAT office is also responsible for the taxes on income from construction work (§ 20a (1) AO). For a firm from Turkey, that is Finanzamt Dortmund-Unna as well.

15 % withholding without a certificate: if your German client is a business, it must as a rule withhold 15 % of each invoice and pay it to the tax office, unless you hold an exemption certificate (Freistellungsbescheinigung) or it pays you no more than €5,000 a year (§ 48 EStG). The certificate requires an authorised recipient in Germany (§ 48b (1) EStG).

What Dortmund-Unna sends by post

• Mitteilung über die Erteilung einer Steuernummer

  Your German tax number

  Confirms your registration. Keep the tax number (Steuernummer) safe. It belongs on every return and every letter you send to the office.

• Erinnerung · Aufforderung zur Abgabe der Umsatzsteuer-Voranmeldung

  Reminder: a VAT return is missing

  The office has not received a return for a period. File it before the deadline in the letter, otherwise surcharges or an estimate may follow.

• Festsetzung eines Verspätungszuschlags

  Late filing surcharge

  A charge because a return came late (§ 152 AO). The letter states the amount and the payment date.

• Bescheid … (Schätzung)

  Estimated tax assessment

  If returns are missing, the office may estimate your tax (§ 162 AO). You can object within one month.

• Benennung eines Empfangsbevollmächtigten

  Request to name an authorised recipient

  The office asks you to name a person or company in Germany who receives letters for you (§ 123 AO).

• Rückfragen · Anforderung von Unterlagen

  Questions or requests for documents

  For example contracts, invoices or proof of your business. Reply in time; if you need longer, ask for an extension before the deadline ends.

Why do you need a German address and an authorised recipient?

German tax offices write in German (§ 87 AO), mostly by post. If your business has no seat in the EU or EEA, the tax office can ask you to name an authorised recipient in Germany (Empfangsbevollmächtigter, § 123 AO).

Marketplace sellers based outside the EU and the EEA must name one with their VAT registration (§ 22f (1) sentence 2 UStG). The VAT registration form for businesses based abroad has its own section for this, called „Empfangsbevollmächtigte(r)“.

If you do not name anyone after the tax office asks you to, a letter posted to you abroad counts as delivered one month after it was sent, unless it is established that it arrived later or not at all (§ 123 AO). That is why the address alone is not enough: someone has to open and read the letter in time.

• Objection (Einspruch): within one month after the assessment is notified (Bekanntgabe, § 355 (1) AO).
• Deadlines in the letter: Many letters set their own date („bis zum …“). That date counts.

How do you contact Finanzamt Dortmund-Unna?

All contact details are on the official page: address, phone numbers, opening hours and appointment booking of Finanzamt Dortmund-Unna are on its page, run by the North Rhine-Westphalia tax administration (linked under Sources). As of 24 October 2026; check the current details there before you call or visit.

• Tax returns: through ELSTER, not by e-mail. A return follows the official form or, where required or allowed, the official electronic data record (§ 150 (1) AO); for VAT the electronic record is required (§ 18 UStG).
• Objection (_Einspruch_): in writing or electronically (§ 357 (1) AO), for example by letter or with the objection form in Mein ELSTER.
• Plain e-mail: fine for simple questions. Where the law requires written form, a plain e-mail does not replace it; that needs a qualified electronic signature or an electronic form of the tax authority such as ELSTER (§ 87a (3) AO).

More on e-mail, ELSTER and your tax number: Contacting the tax office: e-mail, ELSTER, tax number.

What PortoDoc does

1. 01You sign up and sign a power of attorney. You then name PortoDoc to the tax office as your authorised recipient, using the details from your account.
2. 02The tax office writes to our address in Ahrensburg near Hamburg. We scan each letter and you get a notification.
3. 03The letter appears in your account as a PDF. Every plan includes an English AI translation; depending on your plan, you also get an AI summary: non-binding aids, not tax advice; the original letter counts.
4. 04You or your tax adviser reply to the tax office. We do not file returns, give tax advice or monitor deadlines.

Common questions