# Accrued Interest: What It Is, How to Calculate It, and Why It Matters for Bond Investors Published: 2026-04-03 Author: Warren Team URL: https://www.heywarren.com/blog/accrued-interest --- You buy a corporate bond between coupon payment dates. The seller has held the bond for 90 days since the last coupon payment. How much do you owe them for those 90 days of interest they've earned but haven't yet received? The answer is accrued interest, and understanding it is essential for anyone investing in bonds, taking out loans, or managing business accounts. Here's everything you need to know. ## What Is Accrued Interest? Accrued interest is interest that has accumulated on a loan or investment since the last payment date, but has not yet been paid to the holder or received by the lender. It represents the financial obligation or entitlement that has built up over time, even though no cash has yet changed hands. Accrued interest appears in two contexts: 1. **As a liability** (for borrowers): Interest that has built up on a loan or debt since the last payment, you owe it but haven't paid it yet 2. **As an asset** (for lenders/investors): Interest you've earned on a bond or loan since the last coupon/payment date, it's yours but hasn't been received yet In accounting, accrued interest follows the **accrual accounting** principle: revenue and expenses are recognized when they are earned or incurred, not when cash changes hands. ## How Accrued Interest Works in Bond Markets The most important application of accrued interest for investors is in bond trading. Bonds typically pay interest (coupon payments) at fixed intervals, usually semi-annually (every six months). But bonds are bought and sold every day, and secondary market purchases usually happen between coupon payment dates. ![When buying a bond, the dirty price adds accrued interest to the quoted clean price, compensating the seller for interest earned since the last coupon.](data:image/svg+xml,%3Csvg%20xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg%22%20viewBox%3D%220%200%20660%20125%22%20width%3D%22660%22%20height%3D%22125%22%20role%3D%22img%22%3E%3Ctitle%3EFlow%20diagram%3C%2Ftitle%3E%3Crect%20width%3D%22100%25%22%20height%3D%22100%25%22%20fill%3D%22%23f8fafc%22%2F%3E%3Crect%20x%3D%2230%22%20y%3D%2225%22%20width%3D%22170%22%20height%3D%2275%22%20rx%3D%2210%22%20fill%3D%22white%22%20stroke%3D%22%232563eb%22%20stroke-width%3D%222%22%2F%3E%3Ctext%20x%3D%22115%22%20y%3D%2258.5%22%20text-anchor%3D%22middle%22%20font-family%3D%22system-ui%2C-apple-system%2Csans-serif%22%20font-size%3D%2214%22%20font-weight%3D%22600%22%20fill%3D%22%230f172a%22%3EClean%20Price%3C%2Ftext%3E%3Ctext%20x%3D%22115%22%20y%3D%2278.5%22%20text-anchor%3D%22middle%22%20font-family%3D%22system-ui%2C-apple-system%2Csans-serif%22%20font-size%3D%2211%22%20fill%3D%22%2364748b%22%3EQuoted%20market%20price%3C%2Ftext%3E%3Cline%20x1%3D%22205%22%20y1%3D%2262.5%22%20x2%3D%22237%22%20y2%3D%2262.5%22%20stroke%3D%22%2364748b%22%20stroke-width%3D%222%22%2F%3E%3Cpolygon%20points%3D%22244%2C62.5%20235%2C57.5%20235%2C67.5%22%20fill%3D%22%2364748b%22%2F%3E%3Crect%20x%3D%22245%22%20y%3D%2225%22%20width%3D%22170%22%20height%3D%2275%22%20rx%3D%2210%22%20fill%3D%22white%22%20stroke%3D%22%232563eb%22%20stroke-width%3D%222%22%2F%3E%3Ctext%20x%3D%22330%22%20y%3D%2258.5%22%20text-anchor%3D%22middle%22%20font-family%3D%22system-ui%2C-apple-system%2Csans-serif%22%20font-size%3D%2214%22%20font-weight%3D%22600%22%20fill%3D%22%230f172a%22%3E%2B%20Accrued%20Interest%3C%2Ftext%3E%3Ctext%20x%3D%22330%22%20y%3D%2278.5%22%20text-anchor%3D%22middle%22%20font-family%3D%22system-ui%2C-apple-system%2Csans-serif%22%20font-size%3D%2211%22%20fill%3D%22%2364748b%22%3EDays%20held%20by%20seller%3C%2Ftext%3E%3Cline%20x1%3D%22420%22%20y1%3D%2262.5%22%20x2%3D%22452%22%20y2%3D%2262.5%22%20stroke%3D%22%2364748b%22%20stroke-width%3D%222%22%2F%3E%3Cpolygon%20points%3D%22459%2C62.5%20450%2C57.5%20450%2C67.5%22%20fill%3D%22%2364748b%22%2F%3E%3Crect%20x%3D%22460%22%20y%3D%2225%22%20width%3D%22170%22%20height%3D%2275%22%20rx%3D%2210%22%20fill%3D%22white%22%20stroke%3D%22%232563eb%22%20stroke-width%3D%222%22%2F%3E%3Ctext%20x%3D%22545%22%20y%3D%2258.5%22%20text-anchor%3D%22middle%22%20font-family%3D%22system-ui%2C-apple-system%2Csans-serif%22%20font-size%3D%2214%22%20font-weight%3D%22600%22%20fill%3D%22%230f172a%22%3EDirty%20Price%3C%2Ftext%3E%3Ctext%20x%3D%22545%22%20y%3D%2278.5%22%20text-anchor%3D%22middle%22%20font-family%3D%22system-ui%2C-apple-system%2Csans-serif%22%20font-size%3D%2211%22%20fill%3D%22%2364748b%22%3EWhat%20buyer%20pays%3C%2Ftext%3E%3C%2Fsvg%3E) *When buying a bond, the dirty price adds accrued interest to the quoted clean price, compensating the seller for interest earned since the last coupon.* ### The Clean Price vs. Dirty Price When you see a bond's price quoted in financial markets, you're seeing the **clean price**, the price without accrued interest. But when you actually buy the bond, you pay the **dirty price** (also called the full price or invoice price), which includes accrued interest. **Dirty Price = Clean Price + Accrued Interest** This is because the seller has held the bond for some portion of the current coupon period and has earned interest for those days. When you buy the bond, you compensate the seller for that earned-but-not-yet-paid interest. Then, when the next coupon payment arrives, you (as the new holder) receive the full coupon, effectively being reimbursed for the accrued interest you paid at purchase. ### Accrued Interest Formula The formula for calculating accrued interest on a bond is: **Accrued Interest = (Coupon Rate × Face Value) × (Days Since Last Coupon / Days in Coupon Period)** **Example**: You're buying a bond with a 6% annual coupon rate on a $1,000 face value that pays semi-annually. The last coupon was paid 60 days ago, and the coupon period is 180 days. - Semi-annual coupon payment: $1,000 × 6% / 2 = $30 - Accrued interest: $30 × (60 / 180) = $10 You would pay the clean price PLUS $10 in accrued interest. ### Day Count Conventions The "Days in Coupon Period" calculation varies by market and bond type based on **day count conventions**: - **30/360**: Assumes 30 days per month and 360 days per year, common in US corporate and municipal bonds - **Actual/Actual**: Uses actual calendar days, common in US Treasury bonds - **Actual/360**: Uses actual calendar days but a 360-day year, common in money market instruments - **Actual/365**: Uses actual calendar days and 365-day year, common in UK gilts The day count convention affects the exact accrued interest calculation, so it's important to know which applies to the bond you're trading. ## Accrued Interest in Accounting ### For Businesses: Accrued Interest Expense When a company has borrowed money, through bank loans, bonds, or notes payable, it accrues interest expense on those obligations each period. This appears on the balance sheet as **Accrued Interest Payable** (a current liability) until the actual interest payment date. **Journal entry when interest accrues**: - Debit: Interest Expense - Credit: Accrued Interest Payable **Journal entry when interest is paid**: - Debit: Accrued Interest Payable - Credit: Cash This ensures the income statement accurately reflects the cost of borrowing in each period, regardless of when the cash payment occurs. ### For Investors: Accrued Interest Income For companies or individuals holding bonds, notes receivable, or savings deposits, accrued interest represents income earned but not yet received. This appears as **Accrued Interest Receivable** (a current asset) on the balance sheet. **Journal entry when interest accrues**: - Debit: Accrued Interest Receivable - Credit: Interest Income **Journal entry when interest is received**: - Debit: Cash - Credit: Accrued Interest Receivable ## Accrued Interest on Savings Accounts and CDs For savings accounts and certificates of deposit, banks calculate accrued interest daily (based on the annual percentage yield divided by 365 days). This interest typically posts to your account monthly or at maturity, depending on the account type. With certificates of deposit (CDs), accrued interest grows throughout the CD's term. If you redeem a CD before maturity, the bank will pay out the principal plus any accrued interest to that date, minus any early withdrawal penalty. Understanding accrued interest helps you accurately project the total return on fixed-income investments and choose between bonds trading at various stages of their coupon cycle. ## Accrued Interest on Loans and Mortgages For borrowers, accrued interest is the interest that accumulates each day on the outstanding loan balance. Mortgage lenders calculate daily accrued interest as: **Daily Accrued Interest = Annual Interest Rate / 365 × Outstanding Principal** This is why closing on a home late in the month is often slightly cheaper (fewer days of prepaid interest required) than closing early in the month, the days between closing and the end of the month represent accrued interest you must pay upfront. For credit cards and revolving lines of credit, accrued interest compounds daily if balances are carried month to month, which is why high-rate credit card debt grows so quickly. ## Tax Treatment of Accrued Interest **For individual investors in bonds**: Accrued interest you pay when purchasing a bond is typically deductible against the first coupon payment you receive, reducing your taxable income from that coupon. **For bond issuers**: The interest expense accrues and is tax-deductible in the period it accrues under the accrual method of accounting, not just when it's paid. **Specific considerations for municipal bonds**: Tax-exempt municipal bonds still accrue interest daily, but that accrued interest retains its tax-exempt status when it's paid as a coupon. The [IRS Publication 550](https://www.irs.gov/publications/p550) covers the full tax treatment of investment interest income and expense. ## Accrued Interest and Bond Pricing Understanding accrued interest helps explain why bond prices fluctuate even when interest rates haven't changed. As each day passes, accrued interest builds up and increases the dirty price of the bond (what you actually pay), even if the clean price (which reflects only market rate changes) stays constant. ![Accrued interest builds from zero after each coupon payment, peaks just before the next coupon, then resets to zero on payment date.](data:image/svg+xml,%3Csvg%20xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg%22%20viewBox%3D%220%200%20800%20149%22%20width%3D%22800%22%20height%3D%22149%22%20role%3D%22img%22%3E%3Ctitle%3ETimeline%3C%2Ftitle%3E%3Crect%20width%3D%22100%25%22%20height%3D%22100%25%22%20fill%3D%22%23f8fafc%22%2F%3E%3Cline%20x1%3D%22120%22%20y1%3D%2255%22%20x2%3D%22680%22%20y2%3D%2255%22%20stroke%3D%22%23cbd5e1%22%20stroke-width%3D%223%22%2F%3E%3Ccircle%20cx%3D%22120%22%20cy%3D%2255%22%20r%3D%2224%22%20fill%3D%22white%22%20stroke%3D%22%23cbd5e1%22%20stroke-width%3D%222%22%2F%3E%3Ctext%20x%3D%22120%22%20y%3D%2260%22%20text-anchor%3D%22middle%22%20font-family%3D%22system-ui%2C-apple-system%2Csans-serif%22%20font-size%3D%2215%22%20font-weight%3D%22700%22%20fill%3D%22%230f172a%22%3E1%3C%2Ftext%3E%3Ctext%20x%3D%22120%22%20y%3D%22101%22%20text-anchor%3D%22middle%22%20font-family%3D%22system-ui%2C-apple-system%2Csans-serif%22%20font-size%3D%2212%22%20font-weight%3D%22600%22%20fill%3D%22%230f172a%22%3ECoupon%20Paid%3C%2Ftext%3E%3Ctext%20x%3D%22120%22%20y%3D%22119%22%20text-anchor%3D%22middle%22%20font-family%3D%22system-ui%2C-apple-system%2Csans-serif%22%20font-size%3D%2210%22%20fill%3D%22%2364748b%22%3EAccrued%20%3D%20%240%3C%2Ftext%3E%3Ccircle%20cx%3D%22260%22%20cy%3D%2255%22%20r%3D%2224%22%20fill%3D%22white%22%20stroke%3D%22%23cbd5e1%22%20stroke-width%3D%222%22%2F%3E%3Ctext%20x%3D%22260%22%20y%3D%2260%22%20text-anchor%3D%22middle%22%20font-family%3D%22system-ui%2C-apple-system%2Csans-serif%22%20font-size%3D%2215%22%20font-weight%3D%22700%22%20fill%3D%22%230f172a%22%3E2%3C%2Ftext%3E%3Ctext%20x%3D%22260%22%20y%3D%22101%22%20text-anchor%3D%22middle%22%20font-family%3D%22system-ui%2C-apple-system%2Csans-serif%22%20font-size%3D%2212%22%20font-weight%3D%22600%22%20fill%3D%22%230f172a%22%3EDays%20Accumulate%3C%2Ftext%3E%3Ctext%20x%3D%22260%22%20y%3D%22119%22%20text-anchor%3D%22middle%22%20font-family%3D%22system-ui%2C-apple-system%2Csans-serif%22%20font-size%3D%2210%22%20fill%3D%22%2364748b%22%3EDirty%20price%20rises%3C%2Ftext%3E%3Ccircle%20cx%3D%22400%22%20cy%3D%2255%22%20r%3D%2224%22%20fill%3D%22%232563eb%22%20stroke%3D%22%232563eb%22%20stroke-width%3D%223%22%2F%3E%3Ctext%20x%3D%22400%22%20y%3D%2260%22%20text-anchor%3D%22middle%22%20font-family%3D%22system-ui%2C-apple-system%2Csans-serif%22%20font-size%3D%2215%22%20font-weight%3D%22700%22%20fill%3D%22white%22%3E3%3C%2Ftext%3E%3Ctext%20x%3D%22400%22%20y%3D%22101%22%20text-anchor%3D%22middle%22%20font-family%3D%22system-ui%2C-apple-system%2Csans-serif%22%20font-size%3D%2212%22%20font-weight%3D%22600%22%20fill%3D%22%230f172a%22%3EBond%20Traded%3C%2Ftext%3E%3Ctext%20x%3D%22400%22%20y%3D%22119%22%20text-anchor%3D%22middle%22%20font-family%3D%22system-ui%2C-apple-system%2Csans-serif%22%20font-size%3D%2210%22%20fill%3D%22%2364748b%22%3EBuyer%20pays%20accrued%3C%2Ftext%3E%3Ccircle%20cx%3D%22540%22%20cy%3D%2255%22%20r%3D%2224%22%20fill%3D%22white%22%20stroke%3D%22%23cbd5e1%22%20stroke-width%3D%222%22%2F%3E%3Ctext%20x%3D%22540%22%20y%3D%2260%22%20text-anchor%3D%22middle%22%20font-family%3D%22system-ui%2C-apple-system%2Csans-serif%22%20font-size%3D%2215%22%20font-weight%3D%22700%22%20fill%3D%22%230f172a%22%3E4%3C%2Ftext%3E%3Ctext%20x%3D%22540%22%20y%3D%22101%22%20text-anchor%3D%22middle%22%20font-family%3D%22system-ui%2C-apple-system%2Csans-serif%22%20font-size%3D%2212%22%20font-weight%3D%22600%22%20fill%3D%22%230f172a%22%3ENext%20Coupon%3C%2Ftext%3E%3Ctext%20x%3D%22540%22%20y%3D%22119%22%20text-anchor%3D%22middle%22%20font-family%3D%22system-ui%2C-apple-system%2Csans-serif%22%20font-size%3D%2210%22%20fill%3D%22%2364748b%22%3EFull%20coupon%20paid%3C%2Ftext%3E%3Ccircle%20cx%3D%22680%22%20cy%3D%2255%22%20r%3D%2224%22%20fill%3D%22white%22%20stroke%3D%22%23cbd5e1%22%20stroke-width%3D%222%22%2F%3E%3Ctext%20x%3D%22680%22%20y%3D%2260%22%20text-anchor%3D%22middle%22%20font-family%3D%22system-ui%2C-apple-system%2Csans-serif%22%20font-size%3D%2215%22%20font-weight%3D%22700%22%20fill%3D%22%230f172a%22%3E5%3C%2Ftext%3E%3Ctext%20x%3D%22680%22%20y%3D%22101%22%20text-anchor%3D%22middle%22%20font-family%3D%22system-ui%2C-apple-system%2Csans-serif%22%20font-size%3D%2212%22%20font-weight%3D%22600%22%20fill%3D%22%230f172a%22%3EResets%20to%20%240%3C%2Ftext%3E%3Ctext%20x%3D%22680%22%20y%3D%22119%22%20text-anchor%3D%22middle%22%20font-family%3D%22system-ui%2C-apple-system%2Csans-serif%22%20font-size%3D%2210%22%20fill%3D%22%2364748b%22%3ECycle%20repeats%3C%2Ftext%3E%3C%2Fsvg%3E) *Accrued interest builds from zero after each coupon payment, peaks just before the next coupon, then resets to zero on payment date.* On the coupon payment date, accrued interest drops to zero, and the clean and dirty prices are temporarily equal. Then the accrual cycle begins again. This mechanical accumulation of accrued interest is one reason bonds show different effective yields depending on where you are in the coupon cycle, a detail that sophisticated fixed-income investors incorporate into their pricing analysis. ## Conclusion Accrued interest is the financial mechanism that ensures fair compensation across time whenever interest is earned but not yet paid. For bond investors, it means paying the seller for the portion of the next coupon they've already earned. For businesses, it's the proper accounting recognition of interest costs and income in each period. For borrowers, it's the daily accumulation of debt service costs that must be tracked carefully. The fundamental principle is straightforward: interest is earned continuously, even if it's only paid periodically. Understanding this helps you price bonds accurately, plan cash flows, and avoid surprises in both investment returns and borrowing costs. For related reading on fixed-income investing and financial planning, see our guides on [how 1035 exchanges work](/blog/1035-exchange) and [retiring early with financial independence](/blog/retire-early-financial-independence). Get personalized guidance on building an income-generating portfolio with Warren at [heywarren.com](https://heywarren.com), your AI financial advisor helps you navigate bonds, yields, and investment strategy. --- ## Related Reading **More from Warren**: - [Bills Payable: Definition, Examples, and How They Differ From Accounts Payable](/blog/bills-payable) - [Weighted Average Maturity (WAM): Definition, Formula, and Why It Matters for Bond Investors](/blog/weighted-average-maturity) - [Accounts Receivable: What It Is, How It Works, and Why It Matters](/blog/accounts-receivable) **Authoritative sources**: - [FASB, Accounting Standards Codification](https://asc.fasb.org/) - [AICPA, Financial Reporting](https://www.aicpa-cima.com/topic/audit-assurance/financial-reporting) - [SEC EDGAR, Company Filings](https://www.sec.gov/edgar/searchedgar/companysearch)