You need to add at least one vendor before creating invoices. Use Vendors–Add Vendor to add new vendors.

To change existing vendors, first you list them using Vendors–Reports–Search. Vendors are listed with hyperlinks to edit each vendor.

AP–Add Transaction menu adds a new AP Transaction. AP transactions allow you to record your sales in correct GL accounts without creating an invoice.

Vendor invoices are created using AP–Vendor Invoice menu. The only mandatory columns are Vendor and Invoice Date. Rest of the columns can be left blank.

Once you enter an item (part, service) and click 'Update', a new line opens. This way you can enter any number of items (parts, services etc.) in the detail portion of the invoice.

You can record payments from vendor while creating invoices or afterward using Cash–Payment menu option.