Hmmmm...
Sort it as it comes in, rather than once it is in..makes sense. I'll give it a try.
After having slept on it, If I use the known location as the user number, as long as a card reading matches what's in the EEPROM then I can use the location as the ID number. It doesn't really matter what's in there, as long as it is a match.

Thanks heaps Darrel,
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