Most bonds trade “and interest,” which means that the price includes any interest that has accrued on the bond from the time interest was last paid until the day before the settlement date. Most bonds pay interest every six months.
Accrued interest is added to the amount on the buyer’s sales confirmation, because the buyer must pay the price of the security plus the added interest. Accrued interest is also added to the amount on the seller’s confirmation, because he receives the price of the security plus the accrued interest.
When calculating interest, a 30-day month and 360-day year are not assumed for all types of bonds. For example, a Treasury bond assumes the actual days of the month and the actual days in the year. The following table will help you when figuring accrued interest.