Deleting a credit more than 90 days in past

Hello there, RD110.

You don't need to delete the credit. You can set up a clearing account to move it to the correct vendor. Let me guide you with these steps:

First, you'll have to create a clearing account. The clearing account is for moving the existing credit from the vendor.

Second, add a Journal entry to move the credit from the existing vendor to the clearing account:

1. From the Company menu, select Make General Journal Entries.
2. On the first line, credit Accounts Payable with the amount to be transferred. In the Name column, select the vendor from whom the credit is coming.
3. On the second line, debit the Clearing account created in step 1 with the same amount.
4. Select Save & Close.

Then, apply the credit to the journal entry as an unpaid bill. I've added this article for the detailed steps of the process: Apply the credit to the Journal Entry created as an unpaid bill.

You can always get back to this thread whenever you have concerns. 

Why is 90 days important? It doesn't seem like it would matter.

In any case, if the credit is not valid, it seems you can delete or void it without issue.

If the credit is valid, you can disconnect it from the wrong Bill by editing it and changing the vendor name. Then save it, which will un-link it from the bill. Then edit it again and change the vendor name back to the original vendor.