Two different customers pay with a single check.
Customer A and Customer B are owned by the same parent company, and they pay the invoices for both Customer A and B with one check.
Customer A has an open invoice for $150, and Customer B has an open invoice for $100. The parent company writes one check for $250.
A check for $250 is received and applied to Customer A who now has a credit for $100, but Customer B still owes $100.
Move the $100 credit from Customer A to Customer B with two Journal Entries, and then apply the Journal Entries to each customer.
Create the Journal Entries
Receive Payments from Customer A and apply the Journal Entry to the $100 credit
Receive Payments from Customer B and apply the Journal Entry to the $100 invoice
Both customers now have zero balances and the invoices are closed out.