The tax authorities in France has the right to recapture income tax. This general right is usually three years for income tax, ending the third year following the year in which the tax is due (L. 169 of the Tax Procedures Book).
The Government has introduced an exception concerning the 2019 tax return on 2018 income due to the implementation of the CIMR (so called tax credit for the modernization of recovery) allowing not to tax 2018 non-exceptional income under the “white year rules”.
As a result, the tax authorities’ right to check and tax 2018 income will end at the end of the fourth year. The administration can therefore control you and claim an additional tax on your income from 2018 until December 31, 2022, instead of December 31, 2021.