In Germany, you can’t simply add new activities to your existing tax number. Each new business activity must be officially registered with the Finanzamt (tax office).

Depending on the nature of the activity, it could require a separate tax number. Properly managing and tracking each activity’s registration ensures everything stays in order and avoids any issues with tax filings. ✅

When you start a new business activity, it must always be officially registered with the Finanzamt (tax office) through the Fragebogen zur steuerlichen Erfassung (questionnaire for tax registration). This ensures that the tax office has all the information it needs to assess whether you need a separate Steuernummer (tax number) or not.

If your new activity is very different from your current one, the Finanzamt will likely issue a new tax number for that specific activity.

💡 Different business activities can have different tax implications, such as VAT rates. It’s also crucial to keep the revenues and expenses for each activity separate. This helps ensure that your tax filings are accurate and that each activity is treated correctly for tax purposes. Mixing them together could create confusion during tax filing, potentially leading to incorrect calculations or even delays in processing your VAT or income tax returns. By tracking each Steuernummer separately, you’ll keep everything organized and compliant.

However, if your new activity is very similar to your existing one, the Finanzamt may decide to group them under the same Steuernummer. This decision is entirely up to the Finanzamt, and you must wait for their official response.

❗ Regardless, every new activity needs to be properly registered, and you should always wait for confirmation from the Finanzamt before proceeding. This way, you’ll have clarity on whether you’ll be assigned a new Steuernummer or if your activities will be combined.

📂 For more guidance on how to fill out the Fragebogen zur steuerlichen Erfassung, check out our detailed article: How to fill out the Fragebogen zur steuerlichen Erfassung (tax registration questionnaire)

If the tax office decides that your new activity can be managed under your existing tax number, you'll receive an official confirmation. This means you can handle the new activity alongside your existing one under the same tax number.

However, if the tax office determines that a separate tax number is required, you will be informed and receive the new tax number for your activity, inlcuding the tax obligations.

In both cases, you can ensure that your tax declarations are filed correctly and that the activities are properly separated for tax purposes.

If you have multiple activities, you cannot generally use the same Steuernummer for each one. The Steuernummer is directly tied to the activity you’ve registered with the Finanzamt.

❌ This means that you can’t start a new activity using the same Steuernummer as an existing one, as each tax number is associated with the specific business activity you’ve reported.

For example, if you’re running a freelance graphic design business and decide to start a catering business on the side, you’ll need a separate tax number for the catering. Even though both activities fall under the same VAT status (e.g. subject to VAT), they are different in nature, and the Finanzamt will assign a new Steuernummer for the new activity.

💡 It’s essential to keep each tax number linked to the right activity, as it affects how you handle VAT, and other filings. Keeping your activities separate ensures that you stay compliant and organized.

Yes - with some limitations.

You can use Accountable with multiple tax numbers, but you’ll need to create one separate Accountable account per Steuernummer. This ensures that your bookkeeping, expenses, and submissions stay cleanly separated for each activity.

⚠️ Important:
If you have several Steuernummern, you must submit your income tax declaration and VAT declarations with a different tool, for example through Elster.

However, you can submit your EÜR and, if applicable your trade tax declaration through Accountable for each individual account.

This way, everything stays organised, compliant, and easy to manage across all your activities.

📂 For more details, check out our article:

I have 2 or more tax numbers (Steuernummer). Can I use Accountable?

We’ve got the paperwork covered, so you can focus on growing your business. 🚀

Don’t hesitate to contact us whenever you have a question at tax-coach@accountable.eu - we’re here to help and guide you further. 😊