Where Does Interest Income Go on a Business Tax Return?
On Form 1120, interest income is page 1 line 5. On Form 1120-S and Form 1065 it is a separately stated item: it leaves page 1 entirely and is reported on Schedule K, line 4 on an 1120-S and line 5 on a 1065, then flows to the matching box of each K-1.
| Trial balance account | Where it goes on the return | Watch for |
|---|---|---|
| Interest income, C corporation | 1120 page 1 line 5 | Part of total income |
| Interest income, S corporation | Schedule K line 4, not page 1 | K-1 box 4 |
| Interest income, partnership | Schedule K line 5, not page 1 | K-1 box 5 |
| Tax exempt interest | Reported as tax exempt income | Increases basis and AAA |
| Interest on a shareholder loan | Same lines, plus imputed interest rules | Below market rate is a problem |
| Interest expense | A deduction line, never netted here | Separate line entirely |
One account at a time works until there are 200 of them.
Try it freeWhere Does Interest Income Go on a Business Tax Return? on a trial balance
| Acct # | Account | Debit | Credit |
|---|---|---|---|
| 1000 | Cash | 42,800.00 | |
| 1200 | Accounts receivable | 68,500.00 | |
| 1300 | Inventory | 55,000.00 | |
| 1500 | Equipment | 145,000.00 | |
| 1510 | Accumulated depreciation | 47,500.00 | |
| 2000 | Accounts payable | 28,400.00 | |
| 2100 | Accrued expenses | 9,200.00 | |
| 2400 | Notes payable | 92,000.00 | |
| 2450 | Due to shareholder | 15,000.00 | |
| 3000 | Common stock | 10,000.00 | |
| 3900 | Retained earnings | 86,300.00 | |
| 3950 | Shareholder distributions | 52,000.00 | |
| 4000 | Gross receipts (the account this page is about) | 612,000.00 | |
| 5000 | Cost of goods sold | 318,000.00 | |
| 6000 | Salaries and wages | 88,000.00 | |
| 6050 | Officer compensation | 72,000.00 | |
| 6300 | Depreciation expense | 21,500.00 | |
| 6900 | Other operating expenses | 37,600.00 | |
| Total | 900,400.00 | 900,400.00 |
Example journal entries
| Account | Debit | Credit |
|---|---|---|
| Cash | 1,200.00 | |
| Interest income | 1,200.00 |
The entity type changes the answer completely
This is the clearest example in the hub of why a chart of accounts cannot be mapped once and reused across entity types.
On a C corporation, interest income is ordinary income on page 1, line 5, and it is taxed with everything else.
On an S corporation or partnership, interest is a separately stated item. It comes off page 1 entirely, lands on Schedule K, line 4 on an 1120-S and line 5 on a 1065, and flows to the matching box of each owner's K-1.
Why it is separately stated
Because the character of the income has to survive the trip to the owner's return. Interest is not self employment income and is not qualified business income, so it cannot be mixed into ordinary business income without changing what the owner reports.
That is also why the error is invisible on the face of the return. Interest left in gross receipts produces the right total income and the wrong ordinary business income, by exactly the amount of the interest, and every K-1 is wrong in the same way.
On an 1120-S, Schedule K line 4 interest also feeds the investment income figure on line 17a, which the instructions build from Schedule K lines 4, 5a, 6 and 10.
Tax exempt interest is reported too
Municipal interest is not taxable, and it is not invisible. It is reported as tax exempt income, and on a pass through it increases the owner's basis and, on an S corporation, the accumulated adjustments account.
A client whose books lump municipal and taxable interest in one account has to have them split. Reporting the whole balance as taxable overstates income; reporting none of it leaves information off the K-1 that the owner needs.
Interest from a shareholder or partner
The same lines, with an extra question attached. A loan to an owner at below market interest brings the imputed interest rules into play, and the company can end up reporting interest income it never received.
An owner loan that has grown every year with no interest recorded is the common version, and the interest is only part of the problem: the balance itself may not survive as a loan.
Tax return treatment
| Form | Line |
|---|---|
| Form 1120 | Page 1 line 5, interest |
| Form 1120S | Schedule K line 4, and box 4 of each K-1 |
| Form 1065 | Schedule K line 5, and box 5 of each K-1 |
Common questions
What line is interest income on Form 1120?
Page 1, line 5. On a C corporation interest is ordinary income reported with everything else.
Why does interest income not appear on page 1 of an 1120-S?
Because it is a separately stated item. It is reported on Schedule K line 4 and flows to box 4 of each K-1, so the character of the income survives to the shareholder return. On a 1065 it is Schedule K line 5.
What happens if interest is left in gross receipts on a pass through return?
Total income is right and ordinary business income is overstated by the amount of the interest, so every K-1 misstates both ordinary income and separately stated interest. Nothing on the face of the return looks wrong.
Does tax exempt interest get reported?
Yes, as tax exempt income. It is not taxable but it increases owner basis and, on an S corporation, the accumulated adjustments account, so books that combine municipal and taxable interest need the two separated.
Related answers
Go deeper
This page is the short answer. These articles work through the same ground in detail.
Last reviewed October 18, 2026.