Both pence and pennies have existed as plural forms of penny since at least the 16th century. The two forms now tend to be used for different purposes: pence refers to sums of money ( five pounds and sixty-nine pence) while pennies refers to the coins themselves ( I left two pennies on the table). The use of pence rather than penny as a singular ( the chancellor will put one pence on income tax) is not regarded as correct in standard English.
Definition of pence in:
- The US English dictionary