Hello there, @Eve2019.
Let me help you apply the credit to the invoice by verifying the journal entry you created.
Just to clarify, when you create the journal entry, did you use the Accounts Receivable account partnered by Customer Deposit? If not, you'll need to set the Accounts Receivable on the credit side then Customer Deposit on the debit side.
Once done, you can now apply the credit to the invoice.
If you encounter any error when applying payments, you can check out this article for your reference: Resolve Common Issues when Applying a Payment Towards an Invoice.
You can also visit our Help Articles for QuickBooks if in case you need tips and related articles in the future.
Please feel free to post any questions you have below. The Community is always here to help out.
I'd be happy to assist you today, Eve2019.
You've got me here today to provide additional information concerning applying for journal entries as payments via QuickBooks Desktop.
You can set up a deposit or retainer process for your company in QuickBooks Online. The retainer or deposit is treated as a liability to show that, although your business is holding the money from a deposit or retainer, it doesn't belong to you until it's used to pay for services.
So when you invoice the customer and receive payment against it, you'll turn that liability into income. The steps in the following sections will guide you through:
Step 2: Create a retainer item:
You can follow the steps in Step 1 in creating a Trust Liability account. For the other steps, check out this article: https://quickbooks.intuit.com/community/Help-Articles/Manage-upfront-deposits-or-retainers/m-p/20191....
These articles are good references as well:
For additional help, you can also reach out to our QuickBooks Desktop Support.
For more questions, feel free to drop a reply below. I'll be more than willing to lend you a hand.