If hotel uses credit memo to register deposits, it partially covers invoice with damages and have a rest balance. How to write off balance when we return deposit?

Hello there, @irinafrontdesk.

After entering the credit memo, you'll have to create a check to refund the deposit. This will write off the balance in QuickBooks Online.

1. From the + New button, select Check.
2. Select the customer in the Payee field.
3. Under Category details, select Accounts Receivable from the Category field drop-down list.
4. Enter the amount of the deposit received in the Amount field.
5. Once you're done, click on Save and close.

Then, let's record the payment. I'll guide you how:

1. Click to the + New button and then choose Receive Payment.
2. Select the name of the Customer on your invoice. Total Credits should equal the credit memo and invoice listed in the Outstanding Transactions section.
3. Select the checkboxes for the credit memo and invoice in the Outstanding Transactions section.
4. Select Save and Close.

For more details about the process, feel free to browse this article: How to refund a deposit, and close an invoice.

Additionally, you may want to consider recording a retainer or deposit from your customers. This will help you in managing your sales transactions in QuickBooks Online.

I'm always here to lend a hand, @irinafrontdesk. Have a great day!