Yes, I am ending up with duplicate id's. What happened is their entire system crashed and they reloaded the app. This set the key values back to their defaults. So, when they merged this data with the master files, there was a whole slew of dupe values. I guess maybe what I was looking for was some type of key generator that would function similar to the random keys in access. The files are not huge, maybe 50k records or so. Thanks for the input.