Hi there, dorothy wai

I'll guide you on how to allocate a payment to a different invoice within QuickBooks Online.

If QuickBooks has automatically applied a payment to an open invoice and you need to change it to another invoice, you can follow these steps:

1. Go to Customers & leads, then Customers.
2. Select the Customer's profile.
3. Locate the payment and click View/edit option in the Action column.
4. In the Recieve Payment window, under the Outstanding Transactions uncheck the invoice to unlink the payment.
5. Put a checkmark or select the correct invoice to apply for the payment.
6. Then, click on Save and close.

You can check out this article for an alternative option to apply a payment to the appropriate invoice: Fix a payment applied to the wrong invoice in QuickBooks Online.

In addition, if the payment is for another customer invoice, follow this link as a guide: How can I change a payment I've received to a different customer?

If you have any further questions or concerns about invoices and payments, don't hesitate to reach out to us. We are always here to help.