Accountable Plans for S-Corps: How to Deduct Home Office and Business Expenses

The S-Corp Expense Problem

One of the most common surprises for new S-Corp owners: you can no longer deduct unreimbursed business expenses on your personal tax return.

Under pre-TCJA law, employees could deduct unreimbursed business expenses as miscellaneous itemized deductions on Schedule A. The Tax Cuts and Jobs Act of 2017 eliminated this deduction for tax years 2018–2025 (and the TCJA provision has not been extended as of early 2026).

This means an S-Corp owner-employee who pays out-of-pocket for:

• A home office used exclusively for S-Corp work
• Business mileage not reimbursed by the corporation
• Business travel, meals, professional subscriptions

...gets no deduction at all on their personal return.

The fix is an accountable plan — a formal corporate policy under which the S-Corp reimburses employee business expenses, then deducts those reimbursements at the corporate level.

What Is an Accountable Plan?

An accountable plan (IRC § 62(c) and Treas. Reg. § 1.62-2) is a corporate reimbursement arrangement that meets three IRS requirements:

1. Business connection: Reimbursements are only for actual business expenses
2. Substantiation: Employees must substantiate expenses with receipts, logs, or documentation within a reasonable period (typically 60 days)
3. Return of excess: Employees must return any reimbursement that exceeds actual business expenses within a reasonable period (typically 120 days)

When all three requirements are met:

• Reimbursements are not taxable income to the employee
• Reimbursements are fully deductible by the S-Corp as a business expense
• Reimbursements do not appear on the employee's W-2

This is the most tax-efficient way for S-Corp owner-employees to recover business expenses.

The Home Office Deduction Under an Accountable Plan

The home office deduction is where accountable plans provide the biggest benefit for S-Corp owners.

Calculation Method

The home office deduction is based on the percentage of your home used exclusively and regularly for business.

Step 1: Calculate the home office percentage:

Office square footage / Total home square footage = Home office percentage

Example: 200 sq ft office / 2,000 sq ft home = 10%

Step 2: Apply this percentage to eligible home expenses:

Step 3: The S-Corp reimburses the owner-employee $4,150. This is deductible by the S-Corp and not taxable income to the employee. At a combined 32% federal + 6.37% NJ rate, this saves approximately $1,750 in taxes.

Exclusive Use Requirement

The office space must be used exclusively and regularly for business. A guest bedroom that doubles as an office does not qualify. A dedicated room (even if small) used only for business work does qualify. Document this with photos and a written description.

Depreciation on Owner-Occupied Homes

For homeowners, the home office deduction includes a portion of depreciation on the home's structure. This creates a 'recapture' issue when you sell the home — depreciation claimed on the home office must be recaptured as ordinary income at sale, even if excluded from gain under IRC § 121 (the primary residence exclusion).

Many owner-employees choose to exclude depreciation from the accountable plan reimbursement to avoid this recapture issue, especially in high-appreciation markets like NJ.

Other Expenses Reimbursable Under an Accountable Plan

The accountable plan can cover any ordinary and necessary business expense, including:

Mileage

Reimburse business mileage at the IRS standard rate (70 cents per mile in 2025). Employees must keep a contemporaneous mileage log showing date, destination, business purpose, and miles.

Example: Owner-employee drives 5,000 business miles per year. Reimbursement = 5,000 × $0.70 = $3,500, deductible by the S-Corp, not taxable to the employee.

Cell Phone

The business-use percentage of monthly cell phone costs. If the phone is used 70% for business, reimburse 70% of the monthly bill.

Professional Development

Books, courses, conferences, and professional memberships related to the business.

Business Software and Subscriptions

SaaS subscriptions, cloud storage, professional software used for business purposes.

Travel and Business Meals

Business travel (transportation, lodging) is 100% deductible. Business meals with clients or employees are 50% deductible at the corporate level (the S-Corp deducts 50% of the reimbursed meal costs).

How to Set Up an Accountable Plan

Step 1: Adopt a Written Plan

Draft a written accountable plan policy. While not legally required, a written plan is essential for audit protection and employee clarity.

The plan should specify:

• What types of expenses are reimbursable
• Documentation required (receipts, mileage logs)
• Submission timeline (e.g., within 60 days of expense)
• Return-of-excess timeline (e.g., within 120 days of advance)
• Approval process (even for solo owner-employees)

Step 2: Document Expenses

Maintain records for each expense: receipt or log, date, amount, business purpose, and parties involved (for meals). Credit card statements alone are typically insufficient — you need itemized receipts and written business purpose notes.

Step 3: Submit and Reimburse on a Regular Schedule

Establish a regular reimbursement cycle — monthly works well. The owner-employee submits an expense report; the corporation approves and issues a check or bank transfer.

Step 4: Record on the S-Corp Books

The reimbursements must appear in the corporation's accounting records as deductible business expenses — not as distributions or officer compensation.

Step 5: Do Not Include on W-2

Accountable plan reimbursements should not appear in Box 1 (Wages) of the employee's W-2. If they are included on W-2, the deductibility is lost and the employee owes income tax on them.

Accountable Plan vs. Non-Accountable Plan

The non-accountable plan approach (treating reimbursements as additional wages) is the worst of all worlds: the employee pays income tax and FICA on the reimbursements, and the employee cannot deduct the underlying expenses. Avoid it.

NJ-Specific Considerations

NJ GIT Treatment

NJ GIT follows federal law in treating accountable plan reimbursements as nontaxable. Reimbursements properly made under an accountable plan are not included in NJ gross income.

NJ CBT Deductibility

Reimbursements under an accountable plan are deductible by the S-Corp for NJ CBT purposes in the same manner as they are for federal purposes.

NJ Home Office and Property Taxes

NJ has its own home office rules that generally follow federal law. The home office percentage applied to NJ property taxes creates a corporate deduction that partially circumvents the $10,000 SALT cap — since the corporate deduction is not subject to the individual SALT cap.

Frequently Asked Questions

Can a sole proprietor use an accountable plan?

No. Accountable plans are an employer-employee arrangement. Sole proprietors are self-employed and already deduct business expenses directly on Schedule C. An accountable plan is specifically valuable for S-Corp owner-employees who cannot deduct these expenses on their personal returns.

Does every S-Corp need a written accountable plan?

Technically, the IRS does not require the plan to be in writing for it to qualify. But a written plan is strongly recommended for documentation purposes. If audited, a written plan signed before expenses were incurred is much more defensible than claiming you had an informal arrangement.

Can I reimburse myself for prior-year expenses?

No. Accountable plan reimbursements must be substantiated and submitted within a reasonable period after the expense is incurred. Trying to reimburse yourself for years of prior expenses would not meet the plan requirements.

What if I rent office space in my own home to my S-Corp?

Some S-Corp owners formalize the home office arrangement by having the S-Corp pay rent to the owner personally. This approach is legitimate if the rent is reasonable and market-rate, but it creates rental income on the owner's personal return (Schedule E) and may trigger the passive activity rules. The accountable plan approach is generally simpler for most owners.

How does the accountable plan interact with the QBI deduction?

Reimbursements under an accountable plan are deducted at the S-Corp level, reducing S-Corp net income. This in turn reduces the owner's qualified business income (QBI) for purposes of the IRC § 199A deduction. For owners in the QBI phaseout range, larger deductions at the corporate level may reduce QBI. Plan holistically.

Your Accountable Plan Setup Checklist

• Adopt a written plan document. A brief, signed document specifying the plan terms, eligible expenses, and reimbursement procedures. Date it and keep it with your corporate records.
• Open a separate S-Corp bank account. Commingling funds is a leading cause of accountable plan failures and pierced corporate veils. Reimbursements flow from the corporate account to your personal account.
• Set up a monthly submission routine. Gather receipts, complete a simple expense report, and submit to yourself as the S-Corp officer by the end of each month. Consistency matters more than perfection.
• Calculate your home office deduction. Measure the dedicated office space and the total home square footage. Multiply the percentage times actual housing expenses (mortgage interest, real estate taxes, utilities, insurance, repairs). Document the calculation in a spreadsheet.
• Record reimbursements on S-Corp books. Debit the expense account (e.g., 'Home Office Expense'), credit cash. Not payable to a vendor — this comes directly from the S-Corp checking account to you.
• Verify your W-2. Accountable plan reimbursements should NOT appear in Box 1 (wages). If your payroll provider is adding them to your W-2, that's an error — correct it before filing.
• Review Form 1120-S Schedule K. Confirm the home office, mileage, and other reimbursed expenses are properly deducted at the S-Corp level, reducing Box 1 ordinary income.

Sources

• IRC Section 62(a)(2)(A) (accountable plan above-the-line treatment)
• Treasury Regulation § 1.62-2 (accountable plan requirements: business connection, substantiation, return of excess)
• IRC Section 280A (home office rules — exclusive and regular use requirement)
• Rev. Proc. 2013-13 (safe harbor method: $5/sq ft, max 300 sq ft)
• IRS Publication 463 (Travel, Gift, and Car Expenses)
• NJ CBT: N.J.A.C. 18:7-5.4 (S-Corp New Jersey income reporting)

Monaco CPA helps NJ S-Corp owners implement accountable plans, calculate home office deductions, and integrate these strategies with their full tax picture.