Coupon Rate

The coupon rate, also called the stated rate, is the annual interest an issuer contracts to pay on a debt instrument, expressed as a percentage of the instrument’s face amount rather than of its price. Treasury defines the same figure for its own notes and bonds, where interest rate means the annual percentage rate of interest paid on the par amount (or the inflation-adjusted principal) of a specific issue of notes or bonds (31 CFR 356.2). On a fixed-rate instrument it is set at issue and does not move afterwards, so it fixes the rate applied to the principal outstanding for the life of the instrument.

The Formula

Coupon rate  =  annual coupon payments / face amount

annual coupon payments   the cash interest the instrument promises for one full year
face amount              the principal stated on the instrument, repaid at maturity

The denominator is the face amount and never what anyone paid for the instrument, which is what holds the rate still while the price moves. Face amount, par value and face value name that one number, and what else it decides is set out in face amount of a bond.

Say a client holds a bond that pays interest twice a year at a fixed rate on a fixed face amount.

Face amount ($)                                    50,000
Annual coupon payments ($)                          1,750

Coupon rate         1,750 / 50,000            =      3.5%
One payment ($)     1,750 / 2                 =        875
Rate per period     3.5% / 2                  =     1.75%

Fixed at Issue

Treasury bonds pay a fixed rate of interest every six months until they mature, and the rate is fixed at auction and does not vary over the life of the bond (TreasuryDirect, Treasury Bonds).

A floating-rate instrument is the exception, and what stays fixed there is the spread rather than the rate. The spread is the fixed amount over the life of a floating rate note that is added to the index rate in order to determine the interest rate of the note (31 CFR 356.2).

Where the Stated Rate Sits in a Firm’s Work

On the issuer’s books the coupon rate decides the cash, not the expense. Face amount multiplied by the coupon rate gives the interest actually paid, while interest expense follows the effective rate implied by what the debt actually raised, and the schedule that walks discount or premium back to face belongs to bonds payable. The stated rate parts company with the effective rate whenever the proceeds differ from the face amount, which is worked through in effective interest rate formula.

On the holder’s side the same rate sets the cash received. How that amount is measured and reported is interest income, and how much of a coupon has built up between payment dates is accrued interest.

Tax gives the rate a specific job. A cash coupon paid at least annually at a single fixed rate is what lets an instrument’s stated interest count as qualified stated interest, the test set out in face amount of a bond, and it is the rate itself that carries the third of those conditions. Interest is payable at a single fixed rate only if the rate appropriately takes into account the length of the interval between payments, so where the interval varies during the term, the value of the fixed rate a payment is based on generally must be adjusted to reflect a compounding assumption consistent with the length of the preceding interval (Treasury Regulation 1.1273-1(c)(1)(iii)(A)).

Short paper sits outside the test altogether. On a debt instrument with a term that is not more than 1 year from the date of issue, no payments of interest are treated as qualified stated interest payments (Treasury Regulation 1.1273-1(c)(5)), so it is the term of the paper and not what the parties call it that decides whether the stated rate does this job.

What the Coupon Rate Is Not

A Yield

Yield measures the return on what a buyer paid, and the yield to maturity is the annual rate of return on the security (TreasuryDirect, Understanding Pricing and Interest Rates), so it moves with the price while the coupon rate stays where the issue left it.

An Effective or Market Rate

The accounting literature separates them by name: the coupon or stated interest rate is not regarded as the effective yield or market rate (APB Opinion No. 21, footnote 5). The effective rate is the one that discounts an instrument’s payments back to what it actually raised, so it matches the coupon rate only when the instrument is issued at face, a distinction worked through in effective interest rate formula.

A Rate That Compounds Inside the Instrument

A coupon rate is quoted for a year and paid out in cash on the dates the instrument names, so the coupon itself does not compound inside the instrument, while an annual rate quoted elsewhere may carry a compounding instruction that changes the money, as per annum sets out.

Common Questions

Accountably places trained offshore accountants and tax preparers inside US CPA and EA firms, and a firm can put a block of its own debt schedules and interest computations through a trial task before anything client facing depends on it.