To apply for citizenship by naturalisation in France, you must have lived there continuously for at least five years, be over 18, prove your ability to speak and write French to a reasonable standard, be of good character and prove yourself loyal to France.
Accordingly, you must not have been convicted of any criminal offence resulting in a prison sentence of six months or more and you must derive your source of earnings from French soil.
Applications are made to your local prefecture. The procedure includes an investigation of the extent that you have assimilated into French society and takes about 12 months.
The residence requirement is reduced to two years if you have successfully completed at least two years of further education in France or if you are able to render particular service to the French state.
If you marry a French citizen, you are entitled to apply for a declaration of French nationality from the Tribunal d'Instance once you have been married for 12 months. You can make an immediate application however, if you have had a child together and can establish that the child is yours and that you remain co-habiting.
Should a couple fail to continue to live with each other for at least 12 months after the declaration, the marriage will be presumed to have been fraudulent.
Children of French citizens and persons of French mother tongue, going to France from a country where French is an official language, can apply immediately. If a child is born in France, they are entitled to French nationality if they live in France at the age of 18 and have lived at least five years in France between the ages of 11 to 18.
Children born in France of unknown parentage or of stateless parents or who have at least one parent born in France, are entitled to become nationals as of right.
Some nationals permit their citizens to become citizens of one or more foreign states without losing their original nationality.