Provided a bill has been delivered to the executors and you are only transferring the amount on the client ledger, a part payment is acceptable.
In many probate matters, VAT will have been paid to HMRC long before estate funds begin to arrive, so transferring these payments can be important for firm cash flow.
You may wish to confirm with the matter handler that any secured liabilities and funeral expenses have been settled, as these rank ahead of legal fees in the statutory order of priority on insolvent estates which is considered best practice for dealing with all estates
