Hello. My first question is, what revision of FMP do you use or plan to use?, I recommend FMP18 or 19. Second, the column you labeled "RefNumber" is a unique consecutive which only identifies ONE customer?, third, I always like to separate First Name from Last Name, and concatenate them both when listing; that way is much easier to sort by last names, and to do search; but, it is up to you. Fourth, the column labeled 'TxnLine Amount' , is the invoice amount, including tax?, what's the tax percentage, is it fixed or it changes according to the product/service? Fifth, you do not list products or services, so, when invoicing, the file takes the invoice product/service and brings the price automatically, to avoid mistakes when invoicing. Sixth, the 'salesrep" info (names, phones, address, hire date/out, percentage of commission,etc) should be a table on its own; the invoice just chooses the rep from a dropdown list, and calculates the sales commission. I like to id the customer, invoices, products/services, and sales reps with an unique number, it makes it easier to have all types of reports without too much work.