A penny is a unit of currency.

A penny is:

When dealing with British money, amounts of the decimal "new pence" less than 1 may be suffixed with "p," as in 2p, 5p, 26p, 72p. Pre-1971 amounts of less than 1/- (one shilling) were denoted with a "d" which derived from the term "denarius," as in 2d, 6d, 10d.

The plural of "penny" is "pence" when referring to a quantity of money and "pennies" when referring to a number of coins. Thus a coin worth five times as much as one penny is worth five pence, but it is not five pennies, since "five pennies" means five coins each of which is a penny. In the USA, "penny" is normally used only to refer to the coin; the quantity of money is a "cent". A coin worth five times as much as a penny is worth "five cents".

See also: