Introduction
In May 2023, Pfizer sold $31 billion of bonds in eight tranches, one of the largest corporate bond deals ever, to help pay for its acquisition of Seagen. The cash arrived in May; the acquisition did not close until December. In the meantime, Pfizer held the money, earned interest on it, and paid interest on the new bonds. Its interest expense rose almost 80% for the year, to $2.2 billion, but its interest income rose even faster, to $1.6 billion, so its net interest expense actually fell.
Debt touches the three statements in three stages: raising it, paying interest on it and repaying it. Only the middle one affects net income, unless the debt is repaid early. Borrowing and repayment are financing transactions that move cash and a liability, while interest is an expense with a tax effect. Tracing each stage with the method from tracing a transaction through the statements shows why lenders' claims and the cost of those claims appear in such different places.
Raising Debt: Cash and a Liability
When a company borrows, it receives cash and takes on an obligation to repay it. Neither is income or expense. The cash appears in financing activities and the liability on the balance sheet. The costs of issuing the debt, such as underwriting fees and legal costs, are not expensed immediately either: under Accounting Standards Update (ASU) 2015-03, Simplifying the Presentation of Debt Issuance Costs, they are deducted from the carrying amount of the debt and spread over its life as interest expense.
Suppose a company issues $1,000 of ten-year bonds at a 5% coupon and pays $20 of issuance costs:
The income statement is untouched. Cash rises by $980 in financing activities, and debt rises by $980 on the balance sheet: the $1,000 of principal owed, less $20 of unamortized issuance costs. The company still owes the full $1,000 at maturity; the difference will be added to the carrying amount, and to interest expense, over the next ten years. How the face value, carrying amount and fair value of debt differ on the balance sheet is covered in debt on the balance sheet.
Pfizer's 2023 annual report shows the same pattern. Its cash flow statement reports $30.8 billion of proceeds from issuing long-term debt, slightly less than the $31 billion of principal because proceeds are net of discounts and costs, and its debt note shows unamortized discounts, premiums and issuance costs rising from $175 million to $483 million.
Paying Interest: The Recurring Hit to Net Income
Interest is the cost of borrowing, and it is an expense. Under the effective interest method, interest expense includes the cash coupon plus the amortization of any discount or issuance costs, so it exceeds the cash paid when debt was issued at less than face value. For the bond above, the annual coupon is $50, and amortizing the $20 of issuance costs evenly over ten years, an approximation of the effective interest method, adds $2:
Net income falls by $39, the after-tax interest. Cash falls by $37: the $50 coupon paid, less $13 of tax saved. The $2 of amortization is added back on the cash flow statement because it used no cash, and the debt's carrying amount rises by $2 toward its $1,000 face value.
- Interest tax shield
The reduction in income taxes that results from deducting interest expense, equal to the interest multiplied by the tax rate. It makes debt cheaper on an after-tax basis than its coupon suggests, and is the reason after-tax interest, not the coupon, measures the cost of debt to shareholders.
Under US generally accepted accounting principles (GAAP), the interest paid sits in operating activities, not financing, because interest expense is part of net income. The exception is interest capitalized into the cost of a plant or other long-lived asset under construction: that cash is treated as part of the asset's cost and falls in investing activities. Where interest sits on the income statement, and why it is presented below operating income, is covered in interest and other non-operating items.
Accrued and Unpaid Interest
Interest often accrues between payment dates. If a coupon is paid semi-annually and the year ends between payments, the income statement still records the full year's expense, but part of it is unpaid and sits in accrued interest, a current liability. The trace then matches the accrued expense pattern: net income falls by the after-tax interest, the cash flow statement adds back the increase in accrued interest, and cash falls only by the interest actually paid, net of the tax saving. Interest that is not paid in cash at all, but added to the principal (payment-in-kind, or PIK, interest), follows a related pattern traced in PIK interest on the three statements.
Repaying Debt: Principal Never Touches Net Income
Repaying principal at maturity reverses the borrowing. Cash and debt both fall by the amount repaid, the cash outflow appears in financing activities, and the income statement is unaffected. By maturity, the issuance costs have been fully amortized, so the carrying amount equals the $1,000 face value and the repayment leaves no gain or loss. Pfizer's 2023 cash flow statement shows $2.6 billion of payments on long-term debt in financing, alongside the new issuance.
Repaying early is different. If a company retires debt before maturity, it often pays more than face value, because of a call premium, a make-whole payment or a market price above par, while any issuance costs not yet amortized still reduce the carrying amount. Under Accounting Standards Codification (ASC) 470-50, the difference between the price paid and that carrying amount is a loss on extinguishment on the income statement, as Deloitte's guide to extinguishment accounting sets out, so the loss captures both the premium and the unamortized costs written off. On the cash flow statement, the loss is added back in operating activities, and the full cash paid, including any premium, appears in financing activities, the classification set by ASU 2016-15. Buying back debt below its carrying amount, which distressed companies sometimes do, produces a gain instead.
Refinancing in Numbers
A refinancing combines both flows. Suppose a company issues $500 of new notes, ignoring their issuance costs, and uses the proceeds to redeem $500 of existing notes early at 102% of face, paying $510, when the old notes carry $4 of unamortized issuance costs. The loss on extinguishment is $14: the $10 premium plus the $4 written off.
Net income falls by $10.50. The $14 loss is added back in operating activities, so the $3.50 tax saving is the only operating cash effect, while financing shows $500 in and $510 out; cash falls by $6.50 in total. Debt rises by $4, the new $500 against the old notes' $496 carrying amount. The company has replaced its debt, likely at a better rate or maturity, at a one-off cost that bankers exclude from recurring earnings.
What Bankers Take From the Trace
The three stages explain why debt is analyzed through several statements at once. The balance sheet shows how much is owed; the income statement shows its cost, net of tax shields; and the cash flow statement shows whether the company is borrowing, repaying or refinancing. Because principal never reaches the income statement, a company can be comfortably profitable and still struggle to meet a large maturity, which is why credit work focuses on cash flow relative to debt service rather than on earnings alone. The ratios used, such as leverage and interest coverage, are explained in leverage and coverage ratios.
Two further points come from the trace. First, because interest paid is an operating cash flow under US GAAP, operating cash flow less capex is already after interest, and unlevered measures must add after-tax interest back. Second, pre-funding, as Pfizer's year shows, can make net interest expense temporarily misleading: a company that has borrowed ahead of an acquisition carries the debt and the cash at the same time, and only after the cash is spent does the full cost of the new debt appear in its earnings.
