Accountable Plans: The Right Way to Reimburse S-Corp Business Expenses (And What Happens When You Do It Wrong)

S-Corp owners often pay for business expenses out of pocket—mileage, home office, phone, supplies—and then either forget to reimburse themselves or run expenses through the S-Corp account in ways that create tax problems. An accountable plan solves this. It's not complicated, but getting it wrong costs money, and most S-Corp owners either don't have one at all or have one that doesn't actually work.

Why This Matters for S-Corp Owners Specifically

Unlike a sole proprietor, an S-Corp owner-employee cannot deduct unreimbursed employee business expenses on their personal return. Unreimbursed employee business expenses are no longer generally deductible as miscellaneous itemized deductions for most employees. If you pay a business expense personally and the S-Corp does not reimburse you under a proper plan, the business may lose the deduction and you may not have a practical way to deduct it personally.

What Is an Accountable Plan?

An accountable plan is a formal reimbursement arrangement between the S-Corp and the employee-owner that meets three IRS requirements. First, business connection: the expense must be a legitimate business expense. Second, substantiation: the employee must submit receipts or documentation within a reasonable period. Third, return of excess: if the employee receives an advance, they must return any unused amounts within a reasonable time.

When reimbursements are made under a qualifying accountable plan, they are not included in the employee's W-2 wages, not subject to payroll taxes, and fully deductible by the S-Corp as a business expense. This is real money—the difference between getting a deduction and losing it entirely.

What Happens Without One

If the reimbursement arrangement does not meet the accountable plan rules, those reimbursements may be treated as taxable compensation instead of tax-free reimbursements.

How to Set One Up

You need a written policy—typically one to two pages—that establishes the reimbursement framework, an expense report process that captures the business purpose, date, amount, and vendor, and a consistent practice of submitting receipts within a reasonable time (60 days is a common standard). The S-Corp then reimburses the expense and records it as a business expense on the books.

What Can Be Covered

Common items reimbursed under accountable plans include mileage (at the IRS standard rate or actual cost), properly substantiated home office expenses, usually based on actual expenses and business-use percentage, business-use percentage of cell phone, professional development, software and subscriptions, and business meals and travel. This is a simple document that costs almost nothing to implement and can generate real tax savings for S-Corp owners paying business costs out of pocket.