The S corp audit rate sits below 0.05% for tax year 2022 according to the most recent IRS Data Book, meaning fewer than 1 in 2,000 Form 1120-S returns were examined.1Internal Revenue Service. IRS Data Book 2024 – Table 17 That headline number is real, but it hides two things a shareholder needs to know: enforcement is being rebuilt with new funding aimed squarely at pass-through entities, and a handful of filing patterns push individual audit exposure well above the average.
The Current S Corp Audit Rate
The 2024 IRS Data Book reports S corporation examination coverage under 0.05% for tax year 2022. Partnerships and estate and trust returns fell below the same threshold. C corporation returns (Form 1120, excluding S corps) were audited at 0.2% for the same year.1Internal Revenue Service. IRS Data Book 2024 – Table 17
Size changes the picture. For C corporations, audit rates ranged from 0.1% for entities with under $250,000 in assets to 18.2% for those with $20 billion or more. The IRS does not publish an equivalent asset-size breakdown for S corps, but the pattern across every return type is consistent: larger entities draw far heavier scrutiny.1Internal Revenue Service. IRS Data Book 2024 – Table 17
There is also a second audit exposure to keep in mind. S corp income flows through to shareholders’ personal returns, and individual audit rates rise with income. Filers reporting total positive income under $200,000 were audited at 0.1% to 0.4%, while those at $10 million or more were examined at 4.0%.1Internal Revenue Service. IRS Data Book 2024 – Table 17 A high-income shareholder’s Form 1040 carries its own risk independent of the corporate return.
Why the Rate Is Expected to Rise
The sub-0.05% figure reflects years of IRS budget cuts. The Inflation Reduction Act provided roughly $80 billion in new IRS funding, and the agency has publicly committed to directing it at high-income individuals and complex business structures rather than lower-income filers.
The first wave of that work has landed on pass-throughs. The IRS opened examinations of 76 of the country’s largest partnerships, began targeting balance-sheet discrepancies among partnerships with more than $10 million in assets, launched audits of personal use of business aircraft by large corporations, partnerships, and high-income taxpayers, and started deploying artificial intelligence to select complex pass-through returns.2U.S. Department of the Treasury. FACT SHEET: IRS Ramps Up New Initiatives Using Inflation Reduction Act Funding
Most of those initiatives name partnerships and large corporations rather than S corps specifically. The enforcement philosophy, though, runs across all pass-through structures. An S corp with substantial assets, complex transactions, or high-income shareholders should treat the current rate as a floor.
What Actually Triggers an S Corp Audit
Unreasonably Low Owner Compensation
If one issue defines S corp enforcement, it’s reasonable compensation. The tax advantage of an S corp over a sole proprietorship or partnership rests on splitting business profits between W-2 wages (subject to payroll tax) and distributions (not subject to payroll tax). The combined Social Security and Medicare rate is 15.3% on wages. Distributions bypass it. The incentive to set the owner’s salary low and take the rest as distributions is obvious, and the IRS knows it.
Any shareholder who performs services for the corporation must receive reasonable compensation as W-2 wages before taking distributions. The IRS applies a multi-factor test drawn from case law: the shareholder’s duties, training, and experience; time and effort devoted to the business; what comparable businesses pay for similar work; the company’s dividend history; payments to non-shareholder employees; and any compensation formulas in place.3Internal Revenue Service. Wage Compensation for S Corporation Officers
There is no formula that produces the right number. An owner who runs sales, bookkeeping, and operations personally has a different reasonable salary than one who handles only strategy while employees run daily operations. The burden of justification falls on the taxpayer.
When the IRS finds the salary too low, it recharacterizes distributions as wages. A $100,000 distribution reclassified as salary means the corporation owes the employer share of FICA (7.65%), the employee share that should have been withheld (7.65%), penalties for failure to withhold, and interest on the whole underpayment. Combined tax, penalties, and interest on a $100,000 recharacterization can easily exceed $20,000.
The best protection is documentation created before you file: salary survey data (the Bureau of Labor Statistics is a common source), a written description of each role the owner fills, corporate minutes formally approving the compensation figure, and an annual review as the business grows.
Information Return Mismatches
The fastest way to get flagged is a discrepancy between what the S corp reports and what other parties report to the IRS. Automated matching compares amounts on Form 1120-S against corresponding Forms W-2 and 1099. A mismatch, or a missing information return, can generate a correspondence notice before any human examiner sees the file.
Third-party settlement organizations (payment apps, credit card processors) must file Form 1099-K when payments to a payee exceed $20,000 and 200 transactions in a calendar year.4Internal Revenue Service. IRS Issues FAQs on Form 1099-K Threshold Under the One, Big, Beautiful Bill If your S corp receives payments through these platforms, reported totals need to line up with what appears on the return.
Sustained Losses
An S corp that reports net losses year after year invites the IRS to question whether the activity is genuinely operated for profit. Under the hobby loss rules, if a business fails to show a profit in at least three of the past five tax years, the IRS can presume the activity is a hobby and disallow losses that exceed gross income from the activity.5Office of the Law Revision Counsel. 26 US Code 183 – Activities Not Engaged in for Profit The agency weighs time devoted to the business, dependence on the income, changes in method to improve profitability, and the taxpayer’s expertise.6Internal Revenue Service. Is Your Hobby a For-Profit Endeavor? Disallowed losses flow through to shareholders’ individual returns, producing back taxes on the personal side.
High Deduction-to-Income Ratios
Examiners compare deduction levels against industry norms. Travel, meals, and vehicle expenses draw the most challenges because they’re the categories most commonly inflated. An S corp claiming $40,000 in travel deductions on $150,000 in gross receipts, when comparable businesses claim $8,000, should expect questions. Contemporaneous logs and receipts hold up. Records reconstructed after an audit notice arrives do not.
Cash-Intensive Operations
Restaurants, laundromats, convenience stores, and similar businesses face industry-specific audit programs focused on unreported gross receipts. The IRS expects internal controls that reconcile cash on hand with reported income, and gaps in that reconciliation are treated as presumptive underreporting.
Losses Exceeding Shareholder Basis
A shareholder can deduct passed-through losses only up to the adjusted basis in the corporation’s stock plus any direct loans made to the corporation.7Office of the Law Revision Counsel. 26 US Code 1366 – Pass-Thru of Items to Shareholders Losses beyond that amount are suspended and carried forward until the shareholder adds basis. Shareholders must clear four separate hurdles in order: stock and debt basis, at-risk, passive activity loss rules, and the excess business loss limitation.8Internal Revenue Service. S Corporation Stock and Debt Basis Getting any one wrong can disallow the whole deduction.
What It Costs When the IRS Wins
Accuracy-Related Penalty
If an audit reveals an underpayment attributable to negligence or disregard of tax rules, the IRS adds a penalty equal to 20% of the underpayment.9Office of the Law Revision Counsel. 26 US Code 6662 – Imposition of Accuracy-Related Penalty on Underpayments Negligence here means any failure to make a reasonable attempt to comply. It doesn’t require intent to cheat. Taking an unsubstantiated deduction or claiming losses beyond basis can both qualify.
Trust Fund Recovery Penalty
Officers and shareholders responsible for collecting and paying over employment taxes face personal liability if those taxes go unpaid. The trust fund recovery penalty equals 100% of the withheld income tax and employee-share FICA that was not remitted.10Internal Revenue Service. Trust Fund Recovery Penalty (TFRP) Overview and Authority This one pierces the corporate veil. It’s assessed against individuals, not the corporation, and the IRS pursues anyone with authority to direct payment of company bills. The reasonable-compensation issue gets truly dangerous here: an owner who avoids payroll taxes by taking distributions instead of wages can face both recharacterization and a trust fund assessment.
Late Filing
Filing Form 1120-S late triggers a penalty of $245 per shareholder for each month (or fraction of a month) the return is late, up to 12 months.11Internal Revenue Service. Information About Your Notice, Penalty and Interest The amount is adjusted annually for inflation.12Office of the Law Revision Counsel. 26 USC 6699 – Failure of S Corporation To File Return An S corp with five shareholders filing three months late owes $3,675. It applies whether or not tax is owed at the entity level.
How Long the IRS Has to Come Looking
The general audit window is three years from the date Form 1120-S is filed. Filing before the due date starts the clock on the due date; filing late starts it when the return is received.13Office of the Law Revision Counsel. 26 USC 6501 – Limitations on Assessment and Collection
Two exceptions matter. If the S corp omits gross income exceeding 25% of the amount stated on the return, the IRS gets six years.14Office of the Law Revision Counsel. 26 US Code 6501 – Limitations on Assessment and Collection If the return is false or fraudulent with intent to evade tax, or if no return was filed at all, there is no time limit. The IRS can audit indefinitely.13Office of the Law Revision Counsel. 26 USC 6501 – Limitations on Assessment and Collection
Most S corp audits get opened within 18 months of filing. Keep receipts, bank statements, mileage logs, and compensation analyses for at least four years after the filing date to leave yourself a margin.