What makes them think he is in it? I would say you don't but if my company had that my uubby was and ge wasn't I think I would get the solicitor to send a letter or show them just to stop the discussion.
If you aren't in an iva it's none of their business.
If you are using money from an inheritance to help with a full and final for him they could ask I suppose but a letter from the executor should be acceptable.
IVA started March 2011, Completed March 2016 and certificate issued 11 days after final payment. It was not always easy but then some of the best decisions aren't.
None of their business. Your husband must declare any windfalls so if he has none then he has nothing declare. Have they asked to see it abd if so how did they even know about the will anyway?