Hi jacqueline8,
Welcome to the Community! It's great that you're taking advantage of all the features that QuickBooks Online has to offer to make managing your business simple. I can explain how to handle your unapplied credit.
How you'll handle this credit will depend on the situation. If this is a duplicate and the related invoice already has a payment applied to it, then you'll need to delete the credit that was created by the unapplied payment. If this payment was posted through a bank deposit, you'll need to remove the payment line from that deposit or delete the whole deposit in order for the system to let you delete the payment.
If there's an open invoice that this payment relates to, you'll navigate to the invoice and click Receive payment. From there, you can apply the credit that's generated by the unapplied payment to the invoice. This credit will then go away. You can learn more about handling an unapplied payment in this article: Unapplied cash payment income on your profit and loss
If you're still unsure of how to handle this transaction, I recommend checking with your accountant to see how they think it should be taken care of. You can invite your accountant to view your company through the My Accountant tab. If you're not already working with an accountant, you can use the Find a pro to help option to search for a QuickBooks certified Pro Advisor near you.
Please don't hesitate to reach out if there's anything else I can help with!
