Bond Coupon Rate

The bond coupon rate, also called the nominal rate or stated interest rate, is the fixed annual interest rate printed on the face of a bond at issuance. It determines the dollar amount of cash interest the issuer is contractually obligated to pay bondholders each year, calculated as the coupon rate multiplied by the bond's face value, and that cash payment amount never changes over the bond's life regardless of what happens to interest rates in the broader market afterward.

The term survives from the era of physical bearer bonds, which had small, dated coupons attached to the certificate; a holder would literally clip the appropriate coupon and present it to a bank to collect that period's interest payment. Bonds today are almost always registered and pay interest electronically, but the rate they carry is still universally called the coupon rate.

A bond's coupon rate is fixed at issuance, but the market interest rate investors demand on comparable bonds keeps moving afterward. When market rates rise above a bond's coupon rate, the bond becomes less attractive at its original price and trades at a discount below face value; when market rates fall below the coupon rate, the bond becomes more attractive and trades at a premium above face value. This relationship is the core mechanism behind bond discounts and premiums at issuance, and behind ordinary bond price movements in the secondary market afterward.

The coupon rate only tells an investor the cash interest they will receive each year relative to the bond's face value; it does not tell them the bond's true total return if purchased at a price other than face value. That broader measure is the bond's yield to maturity, which accounts for the coupon payments, the price actually paid, and any gain or loss between that price and the face value received at maturity, making yield to maturity the more meaningful figure for comparing bonds trading at different prices.

Even though yield to maturity is the more complete measure of return, the coupon rate remains important because it determines the actual cash the issuer must pay out each period, which matters directly for a company's cash flow planning, and because many bonds are structured with step-up or step-down coupon rates over their life, making the schedule of coupon rates itself a meaningful feature of the security rather than a single static number.

A $1,000 face-value bond with a 5% coupon rate pays $50 in interest each year, split into two $25 semiannual payments for most corporate bonds. If market interest rates later rise to 7% for comparable bonds, this 5% bond becomes less attractive at its original price and will trade below $1,000 in the secondary market, even though its $50 annual coupon payment never changes.

The coupon rate is fixed for the life of the bond and is used only to calculate the dollar interest payment; it is not the same as a bond's actual return to an investor buying it today, which is captured instead by its yield to maturity. A bond's coupon rate and its yield to maturity are equal only at the moment of issuance, when the bond sells at exactly its face value; once the bond trades in the secondary market at a price above or below face value, its yield to maturity moves away from the fixed coupon rate even though the coupon payment itself stays exactly the same for as long as the bond remains outstanding.