Rent amount difference

Hi,

There is a slight difference in the rent amount I mentioned in application and the actual rent.
Actually for some reason I was wrongly paying £10 extra for my rent for almost an year and just came to know recently when i got my tenancy reference letter. My letting agent has sorted it but could this be a problem in my application ? as the amount I mentions and paying is slightly different then what mentioned in my tenancy reference letter, though i am paying extra.