Custom PrimaryKey Generation with autoincrement

Question

I need to define and generate primary key for 2 or more tables.

Tables hold same type of data but FOR Some BUSINESS RULES we have to make them separate say like

Answer 1

I think you should keep them in the same table if at all possible, and add another column to distinguish between local and international customers. With 2 tables, you double all the work you'll need to do in the future on these tables. Not to mention using a calculated varchar id value instead of a simple generated long id.