The Home Office Deduction Works Differently Once You're an S Corp

Everything we've covered in this series so far assumes you're filing Schedule C as a sole proprietor. Once you've elected S corporation status, the home office deduction doesn't disappear, but it stops working the way you're used to, and the mechanics matter a lot more than most S corp owners realize.

Here's what changes, and how to actually claim this deduction once your business is an S corp.

Why you can't just deduct it on your personal return anymore

As an S corp owner working from home, you're not self-employed for tax purposes in the way a sole proprietor is. You're an employee of your own corporation, receiving a W-2 salary, even though you also own the company. That distinction is the whole reason this gets more complicated.

Before 2018, employees with unreimbursed job-related expenses could deduct them as a miscellaneous itemized deduction, and a lot of S corp owners used this route for their home office. That option is gone, and it's gone for good: the deduction for unreimbursed employee business expenses was suspended by the 2017 tax law, and the 2025 tax legislation made that suspension permanent rather than letting it expire as originally scheduled. In plain terms: as an S corp owner-employee, you cannot deduct home office expenses directly on your personal Schedule A, the way you might have years ago, and you cannot deduct them on Schedule C either, because Schedule C is for sole proprietors and your business isn't one anymore.

That doesn't mean the deduction is lost. It means it has to come from a different direction: through the corporation itself.

The right way: an accountable plan reimbursement

The standard, IRS-sanctioned way for an S corp to pick up home office costs is for the corporation to reimburse you, its employee, through what's called an accountable plan. Done correctly, the reimbursement is deductible to the corporation and tax-free to you; no W-2 income, no payroll tax, and no personal-return deduction needed because the money never shows up as your income in the first place.

For a reimbursement plan to qualify as "accountable" in the IRS's eyes, it has to meet three requirements:

Business connection. The expenses being reimbursed have to be genuine business expenses of the corporation. In this case, the business-use portion of your home costs.

Substantiation. You need to actually document the expense: the amount, the business purpose, and reasonable support for the calculation, submitted to the corporation within a reasonable time.

Returning excess reimbursements. If the corporation reimburses you more than your substantiated expenses, you have to return the difference. A plan that just pays a flat amount regardless of actual costs, with nothing ever returned, doesn't qualify as accountable, because reimbursements under a nonaccountable plan are treated as taxable wages instead.

How the reimbursement is actually calculated

This is the part that trips people up most: the $5-per-square-foot simplified method that sole proprietors use isn't available here. An S corp accountable plan reimbursement has to be based on your actual home expenses, calculated the same way the regular method works for a sole proprietor: utilities, homeowners or renters insurance, repairs, depreciation (if you own your home), and similar costs, multiplied by the percentage of your home used exclusively and regularly for the business.

In practice, this means you'll want to go through the same exercise a Schedule C filer would for the regular method: measure your office space as a percentage of your home's total square footage, gather your actual home expenses for the year, and apply that percentage. The corporation then reimburses you that amount, deducts it as a business expense, and you receive it tax-free.

One detail worth flagging if you itemize deductions on your personal return: if you're being reimbursed for the business-use share of your mortgage interest and property taxes through the accountable plan, you generally need to reduce what you claim on Schedule A by that same amount, so you're not deducting the same dollars twice: once through the corporation's reimbursement and again on your personal itemized deductions.

Why renting your home office to your own corporation is usually a bad idea

You may have heard of S corp owners charging their corporation "rent" for use of a home office instead of using a reimbursement plan. We'd steer most clients away from this. The mechanics create a mismatch that rarely works in your favor: the corporation gets a rent deduction, but you have to report that rent as personal income, and you generally can't offset it with your own home office expenses the way you could if you were reimbursed instead, because the personal deduction for those expenses runs into the same unreimbursed-employee-expense wall described above. The net effect is often taxable income to you with little or nothing to offset it. This is a strategy the IRS has scrutinized closely for exactly this reason, and for most S corp owners, an accountable plan reimbursement accomplishes the same goal more cleanly.

What this means if you converted mid-year

If your business moved from a sole proprietorship to an S corp partway through the year, you'll typically end up filing both a Schedule C for the sole proprietor portion of the year and going through the accountable plan process for the S corp portion, since the two structures aren't interchangeable and each has its own home office mechanics. This is exactly the kind of year where getting your home office numbers right matters more than usual, since you're not applying one method uniformly across twelve months.

The bottom line

The home office deduction doesn't go away when you become an S corp owner, it just moves from your personal return into the corporation's books, and it has to be set up correctly to work at all. An accountable plan, calculated on actual expenses rather than the simplified per-square-foot rate, reimbursed regularly and substantiated along the way, is the version of this deduction that actually holds up. If your business has recently made the switch to an S corp, or you've been handling your home office costs some other way, it's worth reviewing how your reimbursements are structured before your next filing.