ELSTER (Elektronische Steuererklärung) is the official portal for tax returns and business registration. For the self-employed, registering with the Finanzamt via ELSTER is the mandatory first step before issuing any invoice.
Step by step
Register on elster.de (activation code arrives by post in about 2 weeks)
Complete the Fragebogen zur steuerlichen Erfassung — state your activity, expected income, and VAT preference
The Finanzamt issues your Steuernummer — it must appear on every invoice
Common mistakes
Losing the ELSTER certificate file without a backup. The certificate (.pfx file) is the only key to your account. If it’s lost and no copy exists, you have to register from scratch and wait for a new activation letter by post.
Estimating expected profit in the Fragebogen too low or too high. This figure sets your income tax prepayments (Vorauszahlungen). Underestimate it and you risk a large back payment later; overestimate it and you tie up cash unnecessarily. If your income changes during the year, ask the Finanzamt to adjust the prepayments.
Assuming every new founder must file VAT returns monthly for the first two years. That blanket rule is suspended for the 2021–2026 tax periods (§ 18 (2) UStG). The Finanzamt sets your actual filing period — monthly, quarterly, or annual — based on turnover. ⚠️ The suspension runs out with 2026: unless lawmakers extend it, from 2027 new businesses again default to monthly filing in their first year and the year after.
Not telling the Finanzamt about changes. A house move, a new bank account, a sharp rise or drop in income — without an update, prepayments and correspondence keep running on outdated information.
I issued invoices before receiving my Steuernummer, writing 'registration in progress'. One client refused to pay until they saw the number. The Finanzamt took 6 weeks. Don't issue invoices before you're officially registered.
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Lea recommends:
I chose the standard VAT scheme (Regelbesteuerung) on €15,000 annual turnover. That meant quarterly VAT returns and extra bookkeeping headaches. For low turnover, the Kleinunternehmerregelung is far simpler.
FREQUENTLY ASKED QUESTIONS
What is the difference between Freiberufler and Gewerbetreibender?▾
Freiberufler (§ 18 EStG) — liberal professions: doctors, lawyers, journalists, IT consultants, translators, architects. No Gewerbesteuer, no trade registration needed. Gewerbetreibende — all others: retail, manufacturing, services. Must register a Gewerbe and pay Gewerbesteuer. The Finanzamt makes the final call on your status.
Do I need to register on day one?▾
Legally: within one month of starting. In practice, register immediately — the Finanzamt takes 4–8 weeks to issue a Steuernummer. Without it you cannot legally issue invoices with VAT.
What is the Kleinunternehmerregelung and is it worth using?▾
Since 2025 there are two limits: up to €25,000 turnover in the previous year AND no more than €100,000 in the current one lets you opt out of VAT (§ 19 UStG). Benefit: no quarterly VAT returns, simpler bookkeeping. Downside: you cannot reclaim input VAT. Good for B2C clients; less useful if you have high VAT-liable expenses.