Is this a vendor payment you issued? Or is this a customer payment that you received?
We are on GP2015. It is possible to unapply the payment from one (or more invoices) and to apply to another or to leave it unapplied on their account.
On vendor payments that you issue, you would have to void the payment. At least as of GP2015.
@Alison Barclay I just learned about this last week. It is accessible when you log in as sa.
Here is a quick view of it.PSTL
If you've found this thread useful, dive deeper into User Group community content by role