Accountable Plans: How to Reimburse Owners and Employees Tax-Free

When a corporation's owner pays for business costs personally, there are two ways the company can put the money back: treat the payment as extra wages (taxable), or reimburse it under an accountable plan (not taxable). The difference is compliance with a short set of rules and the paperwork that shows it.

Where accountable plans matter

An accountable plan is available to employers and employees. In a small business, it matters most where an owner is an employee of a corporation, particularly an S-corp. Owners of sole proprietorships and disregarded LLCs are not employees, so they simply deduct business expenses on Schedule C, and a plan is not needed. Partnerships and multi-member LLCs generally do not use accountable plans for partners, who often handle expenses through unreimbursed partner expense rules or the partnership's expense arrangements.

For S-corp owners, an accountable plan supports:

Reimbursing home office costs (for an owner-employee, the personal home office deduction is generally unavailable, since unreimbursed employee expenses are not deductible under current federal law, so reimbursement through a plan is the usual approach). See home office deduction.
Reimbursing vehicle costs and mileage. See vehicle deductions.
Reimbursing phone and internet, travel, meals, supplies, and professional dues.
Clean separation of business costs from personal. See separating personal and business finances.

The three requirements

Under the IRS regulations, a reimbursement arrangement is accountable if it meets all three:

Business connection. The expenses must be paid or incurred by the employee in connection with performing services as an employee. Personal expenses do not qualify.
Substantiation. The employee must adequately account to the employer for the expenses within a reasonable period. That means providing documentation of the amount, date, place, and business purpose. Receipts, mileage logs, and calendars are typical.
Return of excess. If the employer advances money, the employee must return any amount that exceeds substantiated expenses within a reasonable period.

If any requirement is not met, the arrangement is treated as nonaccountable, and payments are treated as wages subject to income and employment taxes.

Reasonable period safe harbors

The regulations offer safe harbor time frames that are treated as reasonable. Commonly cited ones are: an advance given no earlier than 30 days before the expense, substantiation within 60 days after the expense was paid or incurred, and return of excess amounts within 120 days after the expense was paid or incurred. A periodic statement method is another. Using different timelines is possible if reasonable under the facts. Confirm current guidance with your adviser.

Writing the plan

A written plan is not strictly required by regulation, but it is strongly recommended. A short document should cover:

Who is covered: employees, including owner-employees.
What is covered: categories of business expenses.
How to submit: required documentation and where to send it.
Timing: deadlines to submit and return excess advances.
Rates: the mileage rate or method, and any fixed allowance for items like home office, which must be based on reasonable calculations.
Consequences: unsubstantiated amounts are treated as wages.
Approval: adopted by written consent of the company's board or owners. See corporate formalities and minutes.

Home office reimbursement

For a corporation renting space from an owner or reimbursing the owner for the business portion of home costs, the employer can reimburse a reasonable share of rent or mortgage interest, utilities, insurance, and repairs based on the business-use percentage of the home. The employee should document square footage, the qualifying use of the space, and the costs. Some owners use a per-square-foot rate similar to the simplified method, though whether that is appropriate under an accountable plan depends on the plan's terms and the substantiation approach. A written calculation is essential.

The space should meet the same standards of regular and exclusive business use that the home office deduction rules use, as an indicator of legitimacy. Talk with your tax adviser about how to structure it.

Vehicle reimbursement

Employees using personal vehicles for business can be reimbursed at the IRS standard mileage rate (which is 70 cents per mile for 2025) or by actual expense methods with documentation. A mileage log is the substantiation. It should show the date, destination, business purpose, and miles. Commuting miles between home and a regular workplace are personal, but travel from a qualifying home office to a business destination is business. See vehicle deductions.

Phone, internet, and other recurring costs

Reimburse the business-use percentage of a personal phone or home internet plan. Document how you determined the percentage, such as a usage review or a reasonable estimate maintained with a representative sample of bills. Update the estimate annually.

How it is recorded

The company records reimbursements as business expenses in the appropriate categories (not as wages).
The employee's W-2 excludes the reimbursement.
The employee provides receipts and logs, and the company retains them.
Reimbursement payments should be separate from payroll and clearly labeled in the books.

If some expenses are not adequately substantiated, the payment becomes wages and must be run through payroll.

Common mistakes

Paying a flat monthly amount with no substantiation. A fixed allowance without accounting can be treated as wages unless it is tied to a reasonable estimate of actual expenses and meets the rules for a per diem or mileage allowance.
No documentation. Reimbursing "the home office" without a calculation or evidence.
Reimbursing personal expenses.
Paying the owner from the company account without a plan and calling it an expense.
Not returning excess advances.
Keeping documents only on the employee's phone or in scattered emails.
Failing to adopt the plan in writing.
Reimbursing the owner for expenses that the company should have paid directly.
Applying the plan to a disregarded entity owner who is not an employee, creating confusion.

Reviewing annually

At year-end, review reimbursement totals, spot-check documentation, and reconcile mileage and home office calculations. Update the plan for changes in rates or business needs. Provide the preparer with a summary so the return reflects the correct expense categories. See S-corp mistakes to avoid for other checks.

Alternatives

If a plan is not workable, owners can pay the expense from the company account directly for business items (the simplest solution). For expenses that are mixed personal and business, the accountable plan is the tool. A nonaccountable arrangement (treating reimbursements as wages) is possible but usually not tax efficient.

If you want to adopt an accountable plan or review the one you have, AE Tax Advisors can help, and a discovery call is a good first step.