Before you start

A French tax number, issued after your first declaration
Records of worldwide income for the year
A French bank RIB
Credentials for impots.gouv.fr, once you have a number

Step-by-step

1
Check whether you qualify for the impatriate regime before your first payslip
The régime des impatriés is open to people recruited abroad or transferred into a French entity who were not French tax residents in the five preceding calendar years. It exempts the impatriation bonus and part of foreign-source investment income, and it runs to the end of the eighth year following the year you take up duties. It has to be structured in your contract and payroll, which is why the time to raise it is at offer stage.
Via employerWho: You and your employerAt offer stage
2
Understand that withholding does not replace the declaration
Prélèvement à la source deducts tax from your salary, but the annual declaration in the spring remains mandatory. It reconciles the withholding, applies the household quotient and reliefs, and captures income the withholding never saw.
OnlineWho: YouSpring annually
3
File your first declaration on paper if you have no tax number yet
The online service needs a tax number you do not receive until you have filed once, so the first declaration usually goes on paper to the local tax office. This circularity catches everyone and the office is entirely used to it.
In personWho: You
4
Work out your parts and what the quotient does for your household
A single person counts as one part, a married or PACSed couple as two, with additional half-parts for children. Income is divided by the parts, taxed on the scale and multiplied back. The reduction is substantial for a couple with unequal incomes and for families.
OnlineWho: You
5
Declare every foreign account — the penalty is fixed and it is applied
French tax residents must list all foreign bank accounts, life insurance contracts and digital asset accounts annually, whether or not they generated any income. A dormant account in your home country is exactly the kind of thing that triggers the penalty.
OnlineWho: You
6
Settle your residence position for the year you arrive
France taxes residents on worldwide income. The year of arrival is usually split, with income before the move treated separately, but the treaty with your previous country governs the detail. If you have significant income on both sides of the move, get the first declaration reviewed professionally.
In personWho: You

Documents you’ll need

French tax number, once issued
Payslips and the annual employer summary
The employment contract, for any impatriation bonus
Records of all foreign income and foreign accounts
Marriage or PACS documentation, for household parts

Things most newcomers don’t know

The impatriate regime is worth real money and it is routinely missed by the people it was designed for.

France's régime des impatriés exempts the impatriation bonus and part of foreign-source investment income for people recruited from abroad who were not French tax residents in the five preceding years, running until the end of the eighth year after duties begin. Toulouse recruits internationally at scale, but the benefit depends on how the contract and payroll are structured. Raise it at offer stage — reconstructing it afterwards is far harder than agreeing it up front.

Source: impots.gouv.fr — article 155 B CGI

France taxes the household, which changes the answer completely depending on who you are.

The quotient familial divides household income by a number of parts before applying the scale — one part for a single person, two for a married or PACSed couple, additional half-parts for children. A couple with one high and one low income pays substantially less than two individuals earning the same amounts. A single high earner does comparatively badly. Any comparison of French tax against a country with individual taxation is meaningless without specifying the household.

Source: impots.gouv.fr

You must still file, and your first declaration is usually on paper.

Withholding at source is not the end of the obligation, and the online service requires a tax number you only receive after filing once. Newcomers assume that because tax is visibly coming out of their salary there is nothing to do, and then find themselves reconstructing a missed declaration a year later, with the reliefs and the household quotient never applied.

Source: impots.gouv.fr

Undeclared foreign accounts carry a fixed penalty per account, per year.

French tax residents must list every foreign bank account, life insurance contract and digital asset account annually on a dedicated form, regardless of whether it earned anything at all. The penalty is a fixed EUR 1,500 per undeclared account, rising to EUR 10,000 where the account sits in a state that has no anti-fraud agreement with France, and it is applied rather than theoretical. The account people forget is almost always a dormant one in their country of origin.

Source: impots.gouv.fr

Common mistakes to avoid

Not asking about the impatriate regime before the contract is signed.
Assuming withholding at source removes the obligation to file annually.
Not realising the first declaration goes on paper because you have no tax number yet.
Failing to declare a dormant foreign bank account and incurring the fixed per-account penalty.
Comparing French and foreign tax rates without accounting for household quotient parts.

Some of this may be out of date. Spotted something inaccurate? Help us keep it right for the next newcomer.