The system of 'Pay-As-You-Earn' may
well have been in existence in the UK for a long while now but
it is new and being imposed only now in France .
For many households and certainly
expats living in France , there will be very little practical
difference.
This is because several million households
already elect to pay 'on account' (over 10 months) provisional
payments of income tax to which they may be liable in the year,
based on the tax they paid in the previous year.
However, the double imposition of
income tax in 2019 has meant that the government have been obliged
to forgo tax revenues due on 2018 income - in most cases!