https://www.slab.org.uk/guidance/changes-in-circumstances-and-withdrawal-of-legal-aid/
Your client has a duty to tell us of any change in their circumstances, financial or otherwise.
General rules:
We need to be told as soon as possible of any changes of address so we can update our records. This will avoid delays in correspondence with your client. A notification providing the new address details and, if known, the date the change took place should be sent to us as soon as possible on the reference number/case in question.
Where your client dies you should inform us as soon as possible so we can update our records to prevent us sending any correspondence to the deceased, which could upset family members.