Article 1638 of the French General Tax Code
I. – In the event of the creation of a new commune, different tax rates, with regard to each of the taxes levied pursuant to 1° to 4° of I of Article 1379, may be applied, depending on the territory of the pre-existing communes, during a transitional period. The deliberation instituting this progressive tax integration procedure determines its duration, up to a limit of twelve years. Failing this, the procedure…