I'd like to create an invoice for an advance payment, or deposit. How would I go about creating an invoice to send to a client that asks for the advance vs. the total?

Hello,

Check out the Progress Invoicing feature.  It might help with your situation.

https://quickbooks.intuit.com/ca/resources/updates/new-progress-invoicing-for-quickbooks-online/

Hello @katy42.

Yes, MJA66-87 is correct, we can turn on the progress invoicing feature so we can choose how much we want to invoice on a certain estimate. Progress invoicing allows us to create multiple invoices from an estimate so we can track the progress of a particular job. This also allows us to create multiple partial invoices from a single estimate. That way, we can send an invoice to our clients with only the deposit amount to pay.

To turn on the progress invoicing feature:

1. Go to the Gear icon.
2. Select Account and Settings.
3. Click Sales.
4. Click Progress Invoicing.
5. Put a check mark on Create multiple partial invoices from a single estimate.
6. Click Save.
7. Click Done.

We can now create a progress invoice from the estimate:

1. Go to the Plus (+) icon.
2. Choose Estimate.
3. Enter the information then select Save.
4. Select Create Invoice in the upper right of the estimate. The option will only be available if the estimate is in Pending or Accepted status.
5. Choose how much you want to invoice. 
6. Select Percentage of each line and type in 10%. All the lines are invoiced at a percent of the estimate. You can edit the line amounts or percent.
7. Select Create invoice.
8. If you choose Custom amount for each line, you can enter the desired amount or percentage of each line under Due column.
9. Select Save.

You can also check this article for additional reference: Progress invoicing for QuickBooks Online.

Feel free to add a comment if you have any other concerns. Have a good day!