number too long

[Guest]

i have range a2:a100 that i scan items into, the length of the barcode number
ranges from 10 - 20 digits. when i scan an item that is 20 digits long it
converts the last 5 digits to zeros. i tried formatting the cells to 20 zeros
but then if i scanned something with 10 digits it would add another 10 zeros.
i was thinking of a conditional formatting but i cant seem to get it. please
help
thank you in advance

 

[Tom Ogilvy]

You need to format the cells as Text

Excel only has 15 digits of precision, so if you try to store a number with
more than 15 digits, the digits above 15 will be converted to 0.

 

[Rob van Gelder]

You're reaching the limit of how big a number can be stored.

Try to format the cell as Text instead.