>I would create a new field in the customer table to hold the new customer >number. I would then leave the oldcustomer number as the PK for the customer >table and let the new customer number be a look up field in the customer >table. This will prevent any need to touch any of the other tables at all.

Not totally understanding. What is 'PK'. If I leave the old cust number in the 12 tables I will have a ton of code changes required. Any screen or report that uses a customer number will have to perform a lookup first. Plus how would I handle the indexes that use customer number on the 12 tables. It does not sound possible with my time frame.

Brenda