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

Step-by-step

1
Understand that living in Nice makes you a French tax resident
Your tax residence follows your home, not your employer. If your household is in Nice, France taxes your worldwide income — including a salary paid by a Monegasque employer. Any plan built on the idea that a Monaco job means no income tax needs to be checked before you accept it.
In personWho: YouBefore accepting a cross-border role
2
Take specific advice if Monaco is involved at all
The 1963 Franco-Monegasque convention creates a specific and unusual regime, including the treatment of French nationals resident in Monaco. Whatever your situation, this is a question for an adviser who handles frontalier and Monegasque cases rather than a general French accountant.
In personWho: You
3
Understand that withholding does not replace the declaration
Prélèvement à la source deducts tax from your salary, but the annual spring declaration is still mandatory. It reconciles the withholding, applies the household quotient, and captures income the withholding never saw — which for cross-border earners is often most of it.
OnlineWho: YouSpring annually
4
File your first declaration on paper if you have no tax number
The online service needs a tax number you only get after filing once, so the first declaration usually goes on paper to your local tax office. This circularity catches everybody.
In personWho: You
5
Work out your parts and what the quotient does for you
A single person is one part, a married or PACSed couple two, with additional half-parts for children. Income is divided by the parts, taxed on the scale and multiplied back — a substantial reduction for couples with unequal incomes and for families.
OnlineWho: You
6
Declare foreign accounts, including Monegasque ones
French tax residents must declare all foreign bank accounts, life insurance policies and digital asset accounts annually, whether or not they generated income. A Monegasque salary account is a foreign account for this purpose. The fixed penalty per undeclared account is significant and it is applied.
OnlineWho: You

Documents you’ll need

French tax number, once issued
Salary statements, French or Monegasque
Records of all foreign income and foreign accounts including Monegasque ones
RIB for refunds and payments
Marriage or PACS documentation, for household parts

Things most newcomers don’t know

A Monaco job does not mean no income tax if you live in Nice.

Monaco levies no personal income tax on its residents. Tax residence follows where your home and your household are — so living in Nice makes you a French tax resident, taxed by France on worldwide income including a Monegasque salary. The shorthand that circulates on this coast conflates working in Monaco with living in Monaco, and they are entirely different propositions. Check this before accepting a role, not after your first French declaration.

Source: impots.gouv.fr

The 1963 convention makes French nationals a special case, in the other direction.

Under the Franco-Monegasque convention, French nationals who take up residence in Monaco are generally still taxed by France as though resident in France, with narrow historical exceptions. So the usual advice — move across the border to escape the tax — does not work for French citizens at all. Anyone planning around Monegasque residence needs advice specific to their nationality.

Source: impots.gouv.fr

France taxes the household, and that changes the answer completely.

The quotient familial divides household income by a number of parts before applying the scale. A couple with one high and one low income pays substantially less than two individuals earning the same amounts. Any comparison of French tax against a country with individual taxation is meaningless without specifying the household.

Source: impots.gouv.fr

A Monegasque salary account is a foreign account you must declare.

French tax residents must list every foreign bank account annually, regardless of whether it earned anything, with a fixed penalty per undeclared account. Cross-border workers frequently hold a Monegasque account for payroll and do not think of it as foreign because it is fifteen minutes away. It is, and it must be on the return.

Source: impots.gouv.fr

Common mistakes to avoid

Assuming a Monaco job removes French income tax while living in Nice.
Planning around Monegasque residence without checking the rules for your nationality.
Failing to declare a Monegasque salary account as a foreign account.
Assuming withholding at source removes the obligation to file annually.
Using a general French accountant for a cross-border situation.

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