You should have a field on the invoice of Date Paid, Amount Paid, or both or just a flag as Paid. For the internal working of LINKING a KEY FIELD on the payment would need to be noted on the INVOICE record to tie the invoice to the payment.
Doing a search of your PAID field, for being blank will show those to select for payment.
Are you talking about my current Database for vender or the new "Payment" database that I'm going to create?
If it is the "Payment" database, I have the filed of Amount paid as Bill Amount, and the Date is the payment date.
I don't quite understand your instruction?
What if a single transaction contains multiple bills payment? How do I distinguish them? Can I enter multiple bill number in a single field?
A table for Vendors. A table of Invoices. The invoice table will contain one or more invoices that are to the same vendor awaiting payment. In addition to the fields you noted, you need a field to note if it is paid or not. That could be a Payment Date (blank until paid) or it could be a CheckNumber from the Payment file. Something that by its absence is unpaid.
Below is a quick mock-up in a spreadsheet with basic fields. More can be added to meet you needs. There are two invoices with a blank CkNumber field. These are unpaid. A search for "" in this field will display these. The check number notation can be a link to the payment table.
Is it possible that one payment might be used to pay off more than one invoice?
Is it possible that one payment might pay off a portion of what is owed on a single invoice?
If you answer yes to either question, if there is the slightest chance that you might answer yes either question (and remember that mistakes can be made by the person issuing the checks....) then your system has to become a bit more sophisticated to manage those details.