Exchange Allowance is a term used in the finance industry to refer to the difference between the spot rate and the forward rate of a currency. AGIO is the four letter acronym for this term, which stands for 'Adjusted Gross Interest On Exchange'. Exchange Allowance is the amount of money that a bank or other financial institution will charge for exchanging one currency for another. This fee is usually based on the current market rate of the currency being exchanged. The exchange allowance is an important factor in determining the cost of international transactions.