There are a number of adjustments you can make to transactions.
If a transaction has not been allocated, you can amend transaction references and due dates.
You can unallocate a transaction, using Amend Allocation.
You can reverse a credit note, invoice, payment or receipt transaction, provided:
You cannot reverse a foreign currency transaction.
As a last resort to solve balance problems on a supplier account, if there is no backup available, or to clear test data on your system before applying live data, you can delete transactions.
If you have small values left on your accounts, perhaps due to rounding discrepancies, or you owe a supplier so little that they have written the value off, you can write these values off.