Hi Andrew
Welcome to the forum, you might want to have a look at the following FAQ which explains where everything is
Welcome to Benefits and Work In case you are not aware, your real name appears to be showing in the forum, if you want to change this then follow the instructions in the following FAQ
My full name is showing, how can I stop it?
Yes, the DWP do sometimes ask for bank statements for a period of time, depending on people's circumstances. Typical reasons can be things like proving that a claimant doesn't have more money than they claim to have, show a redundancy payment has all been spent etc etc. If your son is concerned he should ask for more detail.
BIS