[protomyth]

You edit the data type because it isn't a number your importing, its a shipping tag. On import you set the column to text, its right there in the import dialog.

[TeMPOraL]

ID handling 101 - just because it's made only out of digits, doesn't mean it's a number.

[protomyth]

How true that is, dealing with trains, barges, and government issued ids will teach some seriously valuable lessons on that score.