Several of the newspapers are now reporting on the crash of the property market in Spain. I think your mother in law would be seriously advised to hang fire for a while rather than rushing in while the market is in its current disarray. If she waits awhile there may be some excellent bargains on the market as those who have bought at recent high prices go into negative equity and find they are either supporting mortgages for property worth less than they paid for it, or they have to reduce rental prices to uneconomic levels. On the question of which bank to use, possibly her own bank can recommend one, or a UK solicitor who is familiar in dealing with Spanish property transactions. Maybe Googling "Spanish bank for UK residents owning Spanish property" or something similar might produce some leads.