What happens if I don't declare my revenue?

If you don't declare, URSSAF applies a flat penalty. After several missed deadlines, your contributions are calculated on an increased basis. You must declare even if your revenue is 0 euros.

Should I declare monthly or quarterly?

You choose during registration. Monthly declaration is recommended for better cash flow management. Quarterly suits those who prefer less frequent declarations. You can change frequency once a year.

Is the revenue book mandatory?

Yes, it is a legal obligation for all micro-entrepreneurs. It must mention for each receipt: the date, invoice number, client, amount and payment method. Software like Indy generates it automatically.

BeginnerManagementRead 15 minUpdated March 2026

Keep your revenue book

Legal obligation: learn to keep a compliant revenue book.

The 5 key steps

1Understand the obligation (article L123-28 of the Commercial Code)
2Choose a format: Excel, paper or software (Indy, Pennylane)
3Fill in the mandatory information for each receipt
4Date, invoice number, client, amount, payment method
5Keep supporting documents for 10 years

Guide Micro-Entreprise

Editorial team · Business law & Taxation

Updated on 29 January 2026

Verified on official sourcesSources: URSSAF, DGFiP, LegifranceOur methodology

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