Hi,
The form found below, is agreed by both countries as acceptable.
Double Taxation: UK-France (SI 2009 Number 226) (Form France-Individual)
You will need to obtain a letter from the French Tax Authorities, confirming that they refuse to verify the completed form mentioned below, because it is not in French and send the letter to:
H.M. Revenue and Customs Pay As You Earn
BX9 1AS
This is so that our specialist team can liaise with the French tax authorities and work out an agreement.
Thank you.