I have 4 tables all with a primery key which is the reference number and to distinguish between them I have also given each table an ID (A, B, C, and D). What I want to know is if there is any possibility of combining the ref number with the ID on a form thus making a number, for example 63B, or A327. Each table has different sorts of products so I don't want 2 with the same ref. number. If this can't be done, is there any other way I can make the reference numbers different on each table? Any help appreciated.