same happened to me mate , joint mortgage , she moved out , got a letter saying £12000 equity! so she thought she would walk away with at least £6000! ha got on to a mortgage adviser and bye the time you take in to account the redemtion fee for getting out of your agreed mortgage early , solicitors fees , valuation fees and estate agents fees , we would av got £500 each! i offered her £2000 and she took it , so i keep the house. Now we back together and she pays me £400 a month rent hahaha