How to undo a credit

Hello, StoremoreKs.

QuickBooks Desktop will always calculate the amount due based on the outstanding balances less the credits. I have a way to help you remove the credit from the customer statements. 

You can edit the Payment transaction and set the payment amount to $100 (for the previous invoice). Then, create a non-posting credit memo for the $10 overpayment. 

Here's a step-by-step process: 

1. Click the Customers menu, then select Customer Center.
2. Find and select the customer. 
3. Click and open the Payment transaction.
4. Under PAYMENT AMOUNT, set it to $100. 
5. Click Save & Close. Proceed with the changes if it prompts you.

Creating a non-posting credit memo:

1. Open the Customers menu again, then select Create Credit Memos/Refunds.
2. Click the Mark As Pending button.
3. Fill out the details of the credit memo regarding the storage unit overpayment (Add $10 in your case). 
4. Once done, click Save & Close.

The credit memo won't affect your books yet. Your Accounts Receivable account will remain at $100 until you set it as final and apply it on the next invoice. 

Also, this is what your customer statement would look like with the non-posting credit memo:

When you're ready to pay and apply the $10 credit, simply open the credit memo then click the Mark As Final button. 

For reference about customer statements, you can check this article: Create a billing statement.

Need help depositing your payment or reconciling your bank account? Check out these great resources for guides and pointers:

• Record and make bank deposits in QuickBooks Desktop
• Reconcile an account in QuickBooks Desktop

If you have more questions about receiving payments, let me know in the reply section. Do you have any other concerns? Don't hesitate to include them. I'm here to show you a thing or two.