It's a delight to have you here in the Community, @medcure.

Using the credit memo for the overpayments is simple and quick in QuickBooks Desktop (QBDT). I've got steps to help ensure you can achieve this.

First, let's create a credit memo to give money back or credit to your customers. Here's how:

1. Click the Customers menu, and then select Create Credit Memos/Refunds.
   
   
2. Choose a customer name from the Customer: Job drop-down ▼.
3. Enter the items you're giving credit for, and then hit Save & Close once ready.
   
   

Then, you'll be given three options on how to handle it. The following are:

• Retain as an available credit. QuickBooks enters a negative amount in your Accounts Receivable (A/R) register for the credit memo. You can use this credit as payment for another transaction. If you chose to retain as available credit, you'll see the available credits in the customer payment window.
• Give a refund. You can issue the refund in cash, a check, or on a credit card.
• Apply to an invoice. QuickBooks opens the Apply Credit to Invoices window. Select an invoice you want to apply this credit to.

To retain this as an available credit, here's how:

1. Choose the Customers menu, and then click Receive Payments.
2. Select a customer name under the Received from the drop-down ▼, and then tap the Discounts and Credits icon.
   
   
3. On the Credits tab, check the credit you want to apply and then pick Done.
4. You may see a prompt to Confirm transfer. If you do, select Yes. The amount will be applied automatically to the invoice.
5. Hit Save & Close.
   
   

On the other hand, if you prefer the other two options, please check out the Option 2 and 3 section of this article: Credit memo in QBDT.

You can also run and customize the Transaction List by Customer report to show all credit memos. Here are the steps how:

1. Click the Reports menu at the top.
2. On the drop-down (▼) list, click Customers & Receivables and choose Transaction List by Customer.
3. Click the Customize Report button, and then tap the Filters tab.
4. In the filter search box, type, and pick Transaction Type.
5. Under Transaction Type drop-down (▼), choose Credit Memo.
6. Hit OK.
   
   

For more info about customizing reports, see this link: How to customize reports.

To make sure you save the current customization settings of your reports, you may memorize them for easy access. Browse this resource for the detailed steps: Memorize reports.

I'm here to lend a hand if you have more questions about managing your credit memos or anything else related to QuickBooks. Take care and have an awesome day.