Record payment from invoice not in system: suggestions?

Record payment from invoice not in system: suggestions?

I have just switched to using Zoho Invoice. I wanted to start the new year fresh using it exclusively for my invoicing needs. However, I am receiving payments this year for invoices that were sent out from when I was using Quicken.

What is a good way to account for this in Zoho Invoice? Do I make fake invoices with the same number as in Quicken and mark them as paid? Can I just receive a payment without an invoice?

Thanks for any suggestions.

J