Subsequent Debits/Credits are used in cases where the quantity is in the original invoice is to remain the same. For eg.

PO 10 - $10
Gr 10 – $10
LIV 10 - $11 (Logistics Invoice Verification)

The vendor invoice is more than that in the Purchase Order. In order to correct, the Vendor may send in another invoice for
the Increased amount or a credit memo for the increased amount.

If you approve of the price increase, post the subsequent invoice received as a Subsequent Debit/Credit Invoice.

If it is a credit memo that has been received, then post the credit memo as Subsequent Debit/Credit.