Why wont my vendor credit get applied to one of the invoices I am paying

Hello there, @jflynn-neacrylic. Thank you for reaching out to us regarding the issue you're experiencing with applying a vendor credit to a bill in QuickBooks Online. I understand how important it is to apply credits to your invoices properly, and I'm here to assist you.

Typically, when you create a vendor credit and a bill separately in QuickBooks Online, the system generates an expense transaction to apply the vendor credit to the bill. To ensure the credit is applied correctly, please follow these steps:

1. Create an expense transaction: Go to the + icon and select Expense to create a new expense transaction.
2. Fill in the necessary details: Enter the vendor name, date, and the amount of the vendor credit in the expense transaction.
3. Link the vendor credit: In the Category section, select the appropriate expense account for the vendor credit.
4. Apply the vendor credit: Tick the box next to Billable and select the customer associated with the bill you want to apply the credit to.
5. Save the expense transaction.

See the screenshot below for your reference.

Feel free to browse this article for more information about vendor credits: Manage Vendor Credits.

If you need any further support in managing your vendor transactions, please don't hesitate to drop a comment below. I'm here to provide the help you need. Have a restful day!