Welcome to the Community, @mhowell9271.
I'll help you account for customer payments.
QuickBooks supports partial payments for invoices. So once they receive it, they can edit the amount and pay the invoice. Thus, enter the first payer billing information.
Moving forward, reopen the payment link again. Then, edit the amount for the remaining balance. From there, enter the billing information for the second payer. You can refer to the sample screenshot of how it would look like:
I've added this article to view the steps to report partial payments if you are recording the payments manually: Record invoice payments in QuickBooks Online.
Moreover, You can split an estimate into as many invoices as necessary with our Progress Invoicing feature. Instead of requesting full payment, you can invoice your customers for partial payments. To get in-depth information about this feature, check out this link: Set up and send progress invoices.
If you require additional assistance with managing invoices and payments in QBO, you can always reply on this thread. The Community is always open for you. Take care always.