Interest does not wait for a payment date. It builds every day a balance is outstanding. That gap between earning and paying is accrued interest. It shapes what borrowers owe, what investors pay, and how companies report income.
What Accrued Interest Means
Accrued interest is interest earned or owed but not yet paid. The lender or bondholder has earned it. The borrower or issuer owes it.
It shows up on both sides of a contract. A borrower records a liability. A lender records an asset. The amount grows until a payment settles it.
How the Math Works
Most loans use a simple daily formula:
Principal × annual rate ÷ days in year × days elapsed
Take a $10,000 loan at 6%. After 30 days, the interest is $10,000 × 0.06 ÷ 365 × 30. That equals $49.32.
Bonds follow a similar method. Accrued interest equals the annual coupon times days accrued, divided by days in the year. Corporate and municipal bonds use a 360-day year. Treasury securities use actual days.
A $1,000 corporate bond with a 5% coupon pays $50 a year. After 60 days, accrued interest is $50 × 60 ÷ 360. That equals $8.33.
Accounting Treatment
Accrual accounting records interest when it is earned, not when cash moves. This keeps each period’s financials accurate.
Say a company’s interest payment falls after the books close. It still needs an expense for the days already passed. That requires an accrued interest journal entry. The entry debits interest expense and credits interest payable.
The lender mirrors it. It debits interest receivable and credits interest income. When cash arrives, the receivable or payable clears.
Skipping this step understates expenses for the borrower. It understates income for the lender. Both distort profit.
Effect on Loans
Accrued interest changes how a loan behaves over time. Four points matter most:
- Interest accrues daily on the unpaid principal balance.
- Payments usually cover interest first, then principal.
- Unpaid interest can be capitalized, which means it joins the principal.
- Payoff quotes include a per-day amount through the settlement date.
Capitalization is the costly part. Once interest joins the principal, future interest accrues on a larger base. Deferred student loans and some forbearance plans work this way.
Late payments add risk. Interest keeps building while the balance sits unpaid. A borrower who pays early in the cycle can lower the interest charged.
Effect on Bonds and Investments
Bonds pay coupons on set dates. Buyers rarely purchase on those dates. Accrued interest fixes the timing gap.
The buyer pays the seller the interest earned since the last coupon. The buyer then collects the full coupon at the next payment. The net result is fair. Each party gets interest for the days they held the bond.
Two prices matter here:
- Clean price: the quoted price without accrued interest.
- Dirty price: the clean price plus accrued interest.
Your actual cost is the dirty price. Many new investors only look at the clean price. They are surprised when the settlement amount runs higher.
Zero-coupon bonds are different. They pay no coupons, so no accrued interest is paid at trade. Their return comes from the discount to face value.
Tax Considerations
Accrued interest affects taxable income. A buyer who pays accrued interest at purchase can generally offset it against the next coupon when reporting interest. The seller reports the accrued portion as interest income.
Track these amounts on trade confirmations. Brokers list accrued interest separately. Your tax preparer will need it.
How to Check Your Numbers
Do not rely on rough estimates for large trades. Verify them. FINRA offers a free accrued interest calculator for corporate, municipal, and government bonds. It applies the correct day count convention for each type.
For loans, request a payoff statement. It shows principal, interest to date, and the daily rate. Compare it against your own math.
A short checklist helps:
- Confirm the day count convention.
- Identify the last payment or coupon date.
- Count the days elapsed to settlement.
- Compare your result with the lender or broker figure.
Why It Matters
Accrued interest is not a minor detail. It changes loan balances, bond costs, tax reporting, and financial statements.
Borrowers should know when interest capitalizes. Investors should know which price they are really paying. Accountants should record it every period without exception.
Understand the daily build of interest, and the numbers on every statement make more sense.