I think 10.
There are many things that a gift code could be. It could literally be a code you use to get something.
A Minecraft gift code has 12 letters and numbers in the form: a1a1-a1a1-a1a1 (a=any letter, 1=any number)
5
4
You could just keep typing random numbers. Make sure it is a 10 digit number because that is how many characters the code has in it. I hope I helped!
There are 12 numbers.
5
ten
18
It has six letters and five numbers.
There are 14 numbers and letters in a beyblade promo code and i know this because i have many promo codes and they all have 14 numbers and letters.