Applying for French citizenship can be a lengthy process – the average time to process the application is between 18 months and two years, but it can take longer in certain préfectures – so do you have to be living in France for all that time?

The short answer, as so often in France, is ‘it depends’.

In this case it depends how you are applying for citizenship – through marriage, through ancestry, through being born in France (droit du sol) or through residency.

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Marriage – if you are married to a French citizen and are applying through marriage then there is no need to be resident in France. You can apply in the country where you are resident at the time, and the application will be processed through the French consulate. You will, however, need to have been married for at least four years – full details here.

Ancestry – if you have a parent who is a French citizen you can apply through ancestry (and only a parent will do, France does not accept applications through grandparents or more distant ancestors like some countries). In this case, as with applying through marriage, you apply in the country you are resident in and the application is dealt with by the French consulate. If your parent has been out of France for many years, you may need to prove that they maintain a ‘connection’ to the country, such as owning property there are being on the electoral roll for overseas voters – full details here.

Residency – if you have no family or spouse connections to France then you can apply through residency if you have lived in France for five years (the qualifying period can fall to two years if you completed higher education in France). If you are applying through residency then you must have five (or two, as applicable) years of continuous residency.

During the qualifying period you can of course leave France to go on holiday, but France must remain your place of full time residence for the full five (or two) years preceding your application, and you must still be resident when you make the application.

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You also need to remain resident in France while your application is being processed (obviously going on holiday during this period is fine) and the French government stipulates that you must still be resident in France “on the day that the decree is signed”.

Once your application is approved and published in the Journal Officiel, then you are free to leave France and, as a French citizen, you can come and go as you please in the future. It should be noted, however, that you will need to apply for a new French passport once you have your certificate of naturalisation and that process can take a couple of months.

Born in France – a child born in France with at least one French parent is automatically entitled to citizenship from birth, but children born in France to non-French parents can be entitled to citizenship under the droit du sol (birthright) rules. This is something of a bugbear to rightwing politicians and there are regular attempts to toughen up the rules, but here is what the law says at the time of writing.

If the child and their parents are still living in France once the child hits 13, then the parents can apply for citizenship on their child’s behalf provided they are still resident in France and the child has been living in France on a regular basis since the age of eight – full details here.

People born in France can apply for citizenship in their own right once they reach the age of 18 provided; they were living in France at the age of 18 and lived in France for at least five years from the age of 11 and their parents were not diplomatic or consular staff – full details here.

People who fulfil these criteria can apply to become French from outside France, but will usually need to provide proof that they spent a significant part of their childhood in France (eg school records) and were still resident there once they turned 18.

For full details on how to apply for citizenship, check out our Ultimate guide to becoming French