Glad to see you in the Community, katie79.
Let me share some insights about the payment process.
If you use QuickBooks Payments to accept electronic payments, your customers can pay for their invoices online with a credit card, debit card, and ACH bank transfer. After you create and send their invoice, all they have to do is follow the link in the email.
For reference, you can check out this article: Take and process payments with QuickBooks Payments.
On the other hand, if you don’t use QuickBooks Payments, please check out this article on how you can record the payment manually: Record invoice payments in QuickBooks Online.
Please let me know if you have more questions related to customers, or need help with other task in QuickBooks Online. I'll be around to help you out again. Have a good day ahead.
