Do I become a French tax resident if I stay too long at my second home?

Reader question: I have a second home in France and each year I obtain a visitor visa to stay for up to six months. I would like to stay slightly longer using the 90/180 days rule but I fear falling foul of French tax rules about which I hear conflicting ideas. Do I become a French tax resident if I stay longer than six months? I have looked at the US-France tax treaty, but it is still unclear to me. 

Whether you have French tax residency – and thus whether you are obliged to declare worldwide income to France – is dependent on two legal texts, the Code général des impôts (CGI), which lays out what France considers a tax resident, and the US-France double tax treaty which has rules helping clarify marginal cases.

The first CGI rule is where you have your foyer or otherwise your lieu de séjour principal (main place of residency). Case law has clarified that the foyer rule is the main criterion and lawyers say the other is only usually considered if there is no obvious answer to this. 

Your foyer is where you ‘normally’ live and have the strongest personal, family etc ties (eg. where friends and relatives live and where you take part in leisure activities). 

If this cannot be clearly determined, as your life is truly split between two countries, the rule of séjour principal is looked at. This means the country where, in a given year, you spend the most time. 

That can mean ‘more than six months’ but it could be less than that if you lived in several countries during the French tax year. 

The CGI lists two other factors that can cause tax residency to be in France: running most of your financial affairs and having most of your investments in France; and running a business here which is not merely a side income.

The US has its own tax residency rules and, in grey areas, treaty tie-breaker tests include where you have a permanent home available, the ‘centre of your vital interests’ or of ‘habitual abode’ or finally, nationality. Failing all that, the two countries should decide between them.

So: do you immediately become a French tax resident if you stay longer than six months in a given calendar year – not usually (unless you have clearly 'moved to 'France' to make it your main home) but if you habitually spend more time in France than the US and develop stronger ties in France, then yes. 

It is thus advisable to avoid doing so, especially if it is on a repeated basis and if your foyer ties in the US weaken.