We are using Excel to store a 16 digit code for tracking. Unfortunately when
we put in any number that is larger than 15 digits, the last digits are
changed to zero. So a number like 1234567891234567 would be changed to
1234567891234560. A number like 123456789123456789 would be changed to
123456789123456000.

Why would it do this and how do I stop it?

Thanks
Chass
ct