Know what's coming before it lands in your post.

Paper filing is usually due mid-May; online filing is staggered by département into three zones, typically closing between late May and early June. Your foreign bank accounts (Cerfa 3916) get declared in the same return.

Your tax assessment notice — the document that confirms what you owe (or are refunded) and that most agencies ask for as proof of income. Worth filing away; CAF, CPAM, and landlords will ask for it.

Your prélèvement à la source rate (the percentage taken from your salary each month) recalculates based on your latest return. A letter or portal notice confirms the new rate before it applies.

If you own property in France, the bill typically arrives in August or September with payment due mid-October. Monthly payment plans adjust automatically through the year.

If you receive RSA or Prime d'Activité, CAF needs your household income every quarter to recalculate payment. Miss it and payments pause automatically until you file.

Renewal applications for most residence permits open around four months before expiry, via the ANEF online portal. The safe window to actually submit is two to four months before the date on your card.

If you're registered as an auto-entrepreneur, you declare turnover — even if it's zero — either monthly or quarterly, whichever you chose at registration. Due by the end of the following period.

Not government, but a genuinely common trap: French home and auto insurance auto-renews unless cancelled. Insurers must warn you before the renewal date — that letter is your only window to switch or cancel without penalty.