Hi and welcome to the forum. Do you mean when your certificate of compliance of your IVA is received? I believe once this is received any windfalls is yours to keep.
If PPI is due a lot of companies are now requesting this is claimed before completion of IVA to enhance the dividend returned to creditors, this will depend on which company you are with.
IVA final payment left the bank on the 26th January 2013...looking forward to a debt free future.
Your IP is sure to ask you to confirm whether you have any mis-sold PPI to reclaim prior to closing your case. If so, the claim will have to be made during the period of the IVA - so best to let them know about this soonest so the claim can be processed and you case ultimately closed at the earliest opportunity. Until your IVA has closed you will still have to hand over any windfalls received as well.