We need to send invoices to customers that require a 50% upfront deposit payment, with the remaining balance due at the time service is completed.

Hi there, 

Welcome to the QuickBooks Community. It's great to learn you're using the program to help manage your income and expenses for your business. I'll be glad to provide information about handling invoice payments in a way that aligns with what you've described above. 

I see you benefiting more by looking into our feature called Progress Invoicing. This feature enables you to split an estimate into as many invoices as you need. Instead of asking for full payment at the beginning of the project, you can invoice customers for partial payments. I encourage you to check out this helpful article for more info on how to: Set up and send progress invoices in QuickBooks Online. Give this a try and let me know how you make out. 

In case you have other questions, feel free to reach back to me. I'm here to help you achieve your QuickBooks goals.