Ahhh! Panic over exam details!!!?

I have recently sat my A Level exams, and where it says to put your candidate number, I put a '0' before the 4-digit number. I know that's what you do for GCSE but I think you're supposed to put a '2' before it at A Level. Will this have negative effects? e.g. they won't be able to match my grade to my name on the database?? I'm really worried so any answer would be appreciated.