Why this matters
Without tax registration, you often lack the foundation for proper invoices and correct tax classification. At the same time, many founders make decisions in the questionnaire about VAT, the small business rule (Kleinunternehmerregelung), and profit estimates without first understanding what those decisions mean.
Turn knowledge into a start plan
This guide explains one topic. Whether it is really a priority for you right now depends on your answers in the start plan.
Create start planWhat the questionnaire does
The tax registration questionnaire informs the tax office (Finanzamt) that you have started a self-employed activity. It is relevant for commercial, freelance, and agricultural or forestry activities.
You submit it electronically via ELSTER, the official German tax portal. After reviewing it, the tax office issues your tax number (Steuernummer) for your business activity. You need this number to operate in a tax-compliant way and to issue correct invoices.
The questionnaire is not a business plan, but it forces you to state key assumptions: your activity, start date, expected revenue, expected profit, method of profit calculation, and how you will handle VAT.
What information you should typically prepare
Prepare your personal details, address, bank account information, description of your activity, start date, legal form, and any existing tax numbers. For partnerships or companies, you will also need details about the entity and its members.
Particularly important are the estimates: expected revenue, expected profit, and potential VAT. These figures do not need to be perfect, but they should be plausible and consistent with your business model.
If you are starting on the side while employed, you should also have a rough understanding of your income from employment, the scope of your self-employed activity, and your personal financial capacity.
Understanding the small business rule consciously
The questionnaire asks whether you want to apply the Kleinunternehmerregelung (small business rule). This can simplify your start because you do not charge VAT on your invoices as long as the conditions are met.
However, it is not automatically the best choice for everyone. If you sell mainly to businesses, have high initial investments, or plan to grow quickly, the decision may look different. That is why it belongs in your learning phase, not in a quick click.
For current revenue thresholds and detailed rules, always check official sources or consult a tax adviser. This guide and the related card explain the underlying logic, not the binding decision.
VAT, profit calculation, and invoices
The questionnaire influences how the tax office classifies you for tax purposes. This includes VAT, possible advance tax payments (Vorauszahlungen), and the method you use to calculate your profit.
Many small side businesses use the Einnahmen-Überschuss-Rechnung (EÜR), a simplified income-surplus calculation, but this should also fit your situation. What matters is knowing early on which receipts, invoices, and expenses you need to collect properly from day one.
If platforms, EU transactions, B2B customers, or marketplaces are involved, your tax number (Steuernummer), VAT identification number (Umsatzsteuer-Identifikationsnummer, USt-IdNr.), and platform requirements can diverge. These should not be confused with one another.
Why your estimates are not irrelevant
Many founders enter very low or very optimistic figures in the questionnaire because they cannot gauge the impact. A realistic range is better: what do you expect conservatively, what would a good outcome look like, and what costs are involved?
The figures may later differ from reality. But they should show that you have thought through your plans. A side business with 200 euros in annual revenue looks very different from an online shop with inventory, advertising, and ongoing platform fees.
If you are unsure, Freya can help you prepare the questions. The final tax classification, however, belongs with the tax office or a qualified tax adviser.
Quick checklist
- Do you have an ELSTER account, or have you allowed enough time to register for one?
- Can you clearly describe your activity and its start date?
- Have you made rough estimates of your revenue, profit, costs, and a buffer?
- Have you consciously reviewed whether the Kleinunternehmerregelung (small business rule) applies to you?
- Do you know whether a VAT identification number (USt-IdNr.) or platform requirements may become relevant?
- Is it clear how you will collect receipts and invoices from the very start?
Common mistakes
- Only looking for the questionnaire once you already want to issue invoices.
- Ticking the Kleinunternehmerregelung box without thinking through your customer type, costs, and growth plans.
- Mixing up revenue, profit, and personal income.
- Confusing the tax number (Steuernummer) with the VAT identification number (USt-IdNr.).
- Underestimating tax registration as a mere formality.
What this guide can and cannot do
This guide helps with
- create a preparation checklist for the questionnaire for you
- structure your revenue and cost estimates as a thinking framework
- help you distinguish between the Kleinunternehmerregelung, the Steuernummer, and the USt-IdNr.
This guide does not replace
- officially complete or submit the questionnaire on your behalf
- make a binding decision about which tax option is best for you
- replace tax advice or information from the tax office