I have a billing management with the "invoices" table and a "invoice lines" table to insert a portal of items in each invoice.I have this problem: I have three different numbers of the same invoices: a numbering for individuals, a numbering for companies and a numbering for the public administration. Up to now I have managed with more relationships, but now I have to make some substantial changes that complicate me a lot by having this subdivision. I thought it would be nice to be able to manage the three numbers with filters that display the three situations as if they were distinct while maintaining the same table. Is this thought wrong?You do not ask me how, but I realized that I was wrong in the invoice lines that always worked with the "company invoices" report. It worked the same because there was the relationship on the primary key between the bill and the various lines, but I think that having divided into 3 I also had to have 3 distinctions in the lines ... Now we are at the end of the year and I had to think about something else forgetting about the database that I have to restructure.What do you say? Could I have a single invoice and manage only the numbers and a few other items separately?