Hi RosaMaria
There are different reasons why a letter for a compliance interview can be sent out. it could a random selection, it could be because something has been flagged but even if it is the latter, it does not mean that there is a case to answer. They may just be wanting to check that you are receiving the right amount of benefits. At least one member recently found that it was just a simple check.
So I'm afraid unable to tell you what they will ask you as we are unaware of your individual circumstances. If it is done over the telephone and they haven't said otherwise your most recent bank statements should be fine.
BIS
Nothing on this board constitutes legal advice - always consult a professional about specific problems