It is still a matter of national legislation of the domiciled country.
example: In Belgium, there is a specific law for flightcrew that tells that the tax authority lies with the country where the main operational offices of the airline one works for are situated. If you live in Belgium and fly for FR, you pay tax in Ireland. as FR is headquartered in Dublin. If Ireland hands you a certificate that you do not need to pay tax in their country as you are not a resident, then that's it!
I know several guys who did this and even got apology letters from the Belgian authorities as they have no right to even request proof of tax payment due to this law.
By the way: If you get your uniform, roster and holidays schedule from FR, then you are an EMPLOYEE according to EU legislation, and NOT a self-employed pilot.