The best way to find the value of old currency is to consult a dealer or website that specializes in currency collection. The old currency collection market is fluid, making it necessary to find a current price guide.
Old currency is graded on a sliding quality scale, with uncirculated money in mint condition at the top. The extra fine designation is given to notes with few blemishes.
Circulated money is graded according to its appearance after exchanging hands and general wear and tear over the years. Notes in very good condition show signs of creasing and wrinkling. They might be somewhat dirty but are still mainly intact. Good condition is the lowest grade collectors accept. These notes have been heavily used and might be torn in spots. Corners may also be missing. Old coins are similarly graded.
Determining the value of old money depends on several factors. Country of origin is one factor, as collectors value currency from some countries higher than others. Money issued as a commemorative limited edition has more intrinsic value than everyday currency. Dates are an important element in calculating value. Usually, the older the coin or note, the more it is worth. Special marks and signatures with historical significance increase value.