Overpayment on an invoice will cause the remaining balance to be applied to your Trevipay account in the form of a credit. To apply the remaining balance to other invoices or transactions: 

1. Log into the buyer portal at  https://ushipcredit.msts.credit/login
2. Go to Transaction History and select Payments tab
3. Select Modify next to the Remaining balance to apply
4. Once on the Modify Payments page, select the invoice to apply (+ button to left of invoice)
5. Then select open transaction to apply the payment remaining balance
6. Click Next to complete the payment application