Reader question: If I move into my French second home and make it my main residence, how long would it take before it would be considered as such by the tax authorities, for example for purposes of exemption from capital gains tax?
There is no set time period. Assuming you are referring to moving over from outside France, then it will be your main residence once you have established yourself there with the intention to stay. The official tax bulletin states that, for capital gains tax, it should be your “habitual and effective” main residence “for most of the year”. This applies to people who are moving from another home in France but the principle is the same.
One way in which you can establish the move would include writing to the local tax office to tell them it is now your main home, so it should be registered as such for calculation of (or exemption from) taxe d’habitation.
Otherwise, post-Brexit, if you are moving to France from the UK or another non-EU country, your move will in any case be formalised by a long-stay visa, and once in France, a carte de séjour. You would have to specify on applying for the visa that you are moving to France to make it your home.
In due course, you should also be sure to make your annual French tax declaration in the spring for any time living in France as a resident in the previous year (if coming from the UK you should also submit HMRC’s double taxation document ‘form France-Individual’) to confirm you are tax-resident.