You elected S-corp status, you’re paying yourself a salary, and you’re working out of a home office and driving your own car for business. So you go to deduct the home office and the mileage like you always did — and your preparer tells you that you can’t. Welcome to one of the most common surprises of the first S-corp year.
Here’s the issue, in plain terms: once your business is an S-corp, you and the business are two different taxpayers. The home office and the car are personal. The business is what has the expenses. There’s no line on your personal return to deduct unreimbursed employee business expenses anymore — that deduction was eliminated years ago. So if you just eat those costs, the deduction is gone. Not deferred. Gone.
The fix is a tool called an “accountable plan.”
What an accountable plan actually does
An accountable plan is a written policy where your S-corp reimburses you, the owner-employee, for legitimate business expenses you paid personally. When it’s done right, two good things happen at once: the business deducts the reimbursement as a business expense, and the money lands in your pocket completely tax-free — it’s not wages, so there’s no income tax and no payroll tax on it.
Compare that to the wrong way. If you’d taken the same money as extra salary, you’d pay income tax and both sides of Social Security and Medicare on it. The accountable plan turns a taxable dollar into a tax-free one. On a few thousand dollars of home office and vehicle costs a year, that’s real money you’re leaving on the table by not having the plan.
The home office, done correctly
Say your home office is 200 square feet in a 2,000-square-foot home — 10% of the house. You add up the year’s rent or mortgage interest, property tax, utilities, insurance, and repairs, and 10% of that is the business share. If that comes to, say, $4,800 for the year, the S-corp reimburses you $4,800 under the plan. The business deducts it; you receive it tax-free.
This is also the clean answer to a fear a lot of owners carry — that claiming a home office invites an audit. That myth comes from the sole-proprietor world, where the home office sits right on the Schedule C the IRS scrutinizes most. I wrote about why Schedule C returns get audited more than S-corps — and the accountable plan is exactly how an S-corp owner takes the deduction without putting it on that high-scrutiny form.
Mileage and the rest
Same logic for your car. Track your business miles and reimburse yourself at the IRS standard rate — for 2026 that’s 72.5 cents per mile. Drive 6,000 business miles and the plan reimburses you $4,350, tax-free, and the business deducts it. Cell phone, internet, business meals, travel — the legitimate business slice of all of it can flow through the plan the same way.
The three rules you can’t skip
The IRS gives accountable-plan reimbursements their tax-free treatment only if the plan meets three requirements. Miss one and the whole reimbursement becomes taxable wages — which defeats the entire purpose.
Business connection. The expense has to be a real, ordinary business cost — not a personal one dressed up.
Substantiation. You have to document each expense — what it was, how much, when, and the business reason — within a reasonable time. Receipts and a mileage log, not a number you make up in March.
Return of excess. If the business advanced you more than you actually spent, you pay the difference back within a reasonable time. Most owners avoid this entirely by reimbursing actual costs after the fact rather than advancing money.
Practically, that means a one-page written accountable plan adopted by the company, an expense report you submit (monthly or quarterly), and the business cutting you a separate reimbursement — never buried inside your payroll. Keep it clean and it’s bulletproof. And while you’re tightening this up, make sure your salary itself is defensible too; the two issues travel together, which I covered in how to set a reasonable S-corp salary.
The accountable plan is one of the quiet wins of running an S-corp the right way. It doesn’t make headlines, it’s not a loophole, and it takes about an afternoon to set up. But skip it, and you hand back some of the very savings the S-corp election was supposed to give you. Set it up once, use it every month, and let it work.
Geiger Tax & Accounting is based in Amityville, NY and works with business owners nationwide. This article is general information, not tax advice for your specific situation. Accountable plan rules have specific requirements — talk to a professional before implementing. Reach us at (631) 532-5622 or info@geigertax.com.