Dear experts,

I copied an Excel file from other company. The file has 5 columns and 30+
rows. The 3rd column was for card numbers of 12 digits. When I further added
a new record under the last record, the card number I entered was xxxxx..2375
but when I pressed "Enter", the last digit changed to "0" - i.e. xxxxx...2370
instead of 2375. No matter how I change the cell format, it didn't help.
What's the problem of this and how can I fix it. Please kindly advise.

Thanks in advance.