Or maybe don't create a new occurrence at all, just add a field to the table where a value in it identifies a given record as either an estimate or an invoice. You can set up layouts customized for each and you can convert an estimate into an invoice by either changing the value in this field or by duplicating the estimate (and related line items) and labeling the duplicate record as an Invoice in this field.
Yes! I can even create a radio button set or drop-down list based on stages along the process (estimate, pending, follow-up, invoice, collect, etc.) making sorting and reporting easier.
Now, the Status field... should I get rid of it altogether? I don't really need it anymore.
That is a very impressive Starter Solution. I had it on FMP 11 and found it full of bugs. At the time I wasn't capable of fixing it so I dumped it. Now I'm learning FMP 12. It will take some time, but one day soon I will be able to get under the hood, so to speak, and make those necessary tweaks.
Thanks for the tip, much appreciated.