As far as I'm concerned, social charges are another form of tax and I would've thought the title of the post would've been clear enough about what to what I was referring. And I'm aware that these increased rate of social charges weren't applied just because we're British, rather that we are non residents. The system of imposing 15.5% social charges on unearned income of non residents was ruled discriminatory, hence the door being opened for reimbursement demands. However, this hasn't stopped the french government trying to shut the door by re-allocating the funds which the social charges raised. But, I've just found the information I was seeking, elsewhere, so thank you all for your input.