Information is insufficient.

by 'code' i am assuming its asking 'total possible number'

Let me add myself missing information.

1) Number should be of 8-digit .

2) Any digit should not be repeated.

as it's 8 bit to maintain this property first digit can't be 0. so dor first digit 7 combination possible. for second digit also 7 combination possible , for third 6 combo and for forth 5 combo and further in that way.

so total combo = 7*7!