Are Expense Reimbursements Taxable? How They Show on a Pay Stub

When an employee pays for something on the business's behalf — fuel for a client visit, a conference ticket, a box of supplies — paying them back seems simple. For tax purposes, it isn't. The same $200 reimbursement can be completely tax-free or fully taxable wages, and the difference comes down to how the employer's reimbursement policy is set up.

Reimbursement vs. allowance

Start with the two ways money for expenses reaches an employee:

• A reimbursement pays back a specific, documented expense the employee already incurred.
• An allowance or stipend is a flat amount paid regardless of what was actually spent — a fixed monthly phone payment, say, or a car allowance.

Reimbursements can be tax-free. Allowances generally aren't, because nobody has shown the money was spent on business.

Accountable plans: tax-free

A reimbursement arrangement is an accountable plan under IRS rules when it meets three requirements:

1. Business connection — the expense was incurred while doing the job, and would be deductible as a business expense.
2. Substantiation — the employee accounts for the expense within a reasonable time, with receipts or records showing the amount, date, place, and business purpose. The IRS treats 60 days as a reasonable time.
3. Return of excess — any advance beyond what was actually spent is returned within a reasonable time, which the IRS treats as 120 days.

Under an accountable plan, reimbursements aren't wages. There's no federal income tax, Social Security, or Medicare withholding, and the amounts don't appear in Box 1 of the employee's W-2.

Nonaccountable plans: taxable wages

If any of those requirements isn't met — no receipts required, excess advances never returned, or a flat allowance — the payments fall under a nonaccountable plan. They're treated as supplemental wages:

• Included in the employee's taxable wages and W-2 Box 1.
• Subject to income tax withholding, Social Security, and Medicare.
• Subject to the employer's share of payroll taxes, too.

That makes a nonaccountable plan expensive for both sides. A $100 phone stipend might leave the employee with around $70 after withholding, while the employer also pays its share of FICA on top.

Mileage and per diem

Two common reimbursements have IRS shortcuts that count as substantiation of the amount:

• Mileage — reimbursing business miles at no more than the IRS standard mileage rate keeps the payment tax-free, as long as the employee logs the dates, miles, and business purpose of each trip. The IRS publishes the rate each year and occasionally revises it mid-year, so check the current figure.
• Per diem — for business travel, paying a daily rate for lodging, meals, and incidentals up to the federal per diem rates for the location avoids the need for individual meal receipts. The employee still records dates, place, and purpose.

Anything paid above those rates is taxable wages unless the excess is returned.

How reimbursements appear on a pay stub

Employers handle this in one of two ways. Some pay reimbursements separately from payroll, by bank transfer or check, so they never touch the stub. Others add them to the regular paycheck as a non-taxable line — often labelled "Reimbursement" or "Expense reimb." — that increases net pay without increasing taxable wages.

When reimbursements ride along with a paycheck, the stub should make the distinction visible. A tax-free reimbursement adds to net pay without changing the tax withheld. If a reimbursement is instead added to gross earnings and taxed, it's being treated as wages — correct for an allowance, but worth questioning if you submitted receipts.

Decoding pay stub abbreviations covers the other codes you'll see alongside it.

State reimbursement laws

Federal law doesn't require employers to reimburse business expenses, with one important exception: for non-exempt employees, unreimbursed costs the employer requires can't push their pay below minimum wage. Several states go much further. California and Illinois, among others, require employers to reimburse necessary business expenses — which can include part of a personal phone bill used for work.

For employers: set up a written policy

A short written accountable-plan policy is the simplest way to keep reimbursements tax-free. It should say what's reimbursable, what documentation is required, the deadline for submitting it, and what happens to unspent advances. Then apply it consistently: a plan that routinely skips receipts can be treated as nonaccountable in full.

If you're new to running payroll, the small business payroll checklist covers the rest of the setup.

This article is general information, not tax advice. Check IRS Publication 463 and Publication 15 or a tax professional for your situation.