You just sent an employee to a three-day client meeting in Chicago. They come back with a stack of crumpled receipts: a $289 hotel folio, $18 airport sandwiches, $42 in Uber tips, and a $9 bottled water from the minibar. Do you reimburse every line item, or could you have just paid a flat daily rate and skipped the paper chase entirely?
That question — per diem versus actual expenses — is one of the most practical decisions a growing business makes about travel. Get it right and you save hours of bookkeeping, keep reimbursements tax-free, and stay clean in an IRS audit. Get it wrong and those reimbursements become taxable wages, complete with payroll tax and W-2 headaches.
Here is how both methods work in 2026, when each makes sense, and the three accountable-plan rules that determine whether any travel reimbursement stays tax-free.
What "Per Diem" Actually Means
Per diem (Latin for "per day") is a fixed daily allowance you pay an employee for lodging, meals, and incidental expenses while they are traveling away from home on business. Instead of tracking every receipt, you pay a set amount for each day of travel. If the allowance is within the federal limit and properly documented, the employee does not pay income tax on it, and you do not withhold payroll tax.
The alternative — actual expenses — is exactly what it sounds like: the employee pays for everything out of pocket, submits receipts, and you reimburse the exact amounts.
Both are legitimate. The difference is administrative burden, cost control, and audit risk.
The Two Federal Rate Systems You Need to Know
The IRS does not invent per diem rates from scratch. It recognizes two systems, both updated each federal fiscal year on October 1:
1. GSA per diem rates (the detailed method). The General Services Administration publishes a rate for virtually every city and county in the continental United States (CONUS). Each location gets a lodging rate and a meals-and-incidental-expenses (M&IE) rate. High-cost cities like San Francisco, New York, and Washington, D.C., have higher rates; most other locations default to the standard rate. Outside CONUS, the State Department sets rates. These are the rates federal employees use, and any private employer can adopt them.
2. IRS high-low method (the simplified method). For employers who do not want to look up every city, the IRS publishes just two rates in an annual notice. For travel on or after October 1, 2025, through September 30, 2026 — the period covered by IRS Notice 2025-54 — the rates are:
- High-cost locality: $319 per day — broken down as $233 for lodging and $86 for M&IE
- All other CONUS localities: $225 per day — broken down as $151 for lodging and $74 for M&IE
- Incidental-expenses-only rate: $5 per day — for days when you provide lodging but need to reimburse only tips and fees to porters, baggage carriers, and hotel staff
- Transportation industry M&IE-only rate: $86 high / $74 low — used by employers in the transportation industry who pay only meals and incidentals
The IRS also publishes a list of high-cost localities each year — generally places where the federal per diem rate is $259 or higher. If your destination is on that list, you use $319; otherwise, $225. You can switch between the GSA detailed rates and the high-low method year to year, but you cannot flip methods mid-year for the same employee.
For fiscal 2026, the IRS kept the high-low rates unchanged from the prior year, a sign of stable lodging and meal costs after several years of increases.
Per Diem vs. Actual Expenses: Head-to-Head
How Each Method Works Day-to-Day
With per diem:
- Before the trip, you tell the employee the daily rate for their destination. For example: three days in a high-cost city at $319 per day equals $957, regardless of what they actually spend.
- The employee still documents the time, place, and business purpose of the trip — but does not need to save every meal receipt.
- You reimburse the fixed amount. If you pay at or below the federal rate, the full amount is deemed substantiated.
With actual expenses:
- The employee pays for lodging, meals, transportation, and incidentals and keeps every receipt.
- They submit an expense report with dates, amounts, locations, and business purpose.
- You reimburse the exact total. Lodging requires receipts in all cases; meals under $75 can sometimes be documented without a receipt if you have a written accountable plan, but most accountants advise keeping them anyway.
When Per Diem Wins
Per diem shines when travel is frequent, predictable, or to a handful of destinations. A consulting firm that sends the same team to client sites every week, a contractor bidding on out-of-town jobs, or a sales team covering a region will save hours each month by avoiding receipt-by-receipt reconciliation.
It also helps with budgeting. You know a five-day trip to a standard-rate city will cost $1,125 ($225 x 5) in lodging and M&IE before anyone packs a bag. Employees know what to expect, too, which reduces disputes over whether a $28 lunch was "reasonable."
Crucially, for lodging plus M&IE per diem, the employee can keep any amount they do not spend without it becoming taxable — as long as the per diem does not exceed the federal rate and the trip is properly substantiated. That creates a natural incentive to travel economically.
When Actual Expenses Win
Actual expenses are better when costs vary wildly or when per diem would overpay. A few examples:
- Short trips with cheap lodging. If your employee stays with a client or at a $129 roadside hotel but the high-low rate assumes $233 for lodging, you would over-reimburse with per diem.
- Long stays. For assignments lasting weeks, actual cost tracking often beats a per diem that was designed for short-term travel.
- Mixed M&IE situations. If you already provide meals — say, a conference includes lunch — reimbursing a full M&IE per diem double-pays the employee. Actual expenses let you reimburse only what was actually incurred.
- International travel. The high-low method covers only CONUS. International per diems use State Department rates, and actual expenses can be simpler if you travel to one country infrequently.
You can also use a hybrid: reimburse lodging at actual cost (with receipts) and use per diem only for M&IE. Many small businesses do exactly this because lodging is the most variable cost and the easiest to document with a single hotel folio.
The Three Rules That Make Reimbursements Tax-Free
The method you choose does not determine tax treatment. Your accountable plan does. Under IRS Publication 463 and related guidance, reimbursements are excludable from the employee's wages only if all three accountable-plan requirements are met:
1. Business connection
The expense must be ordinary and necessary, incurred while the employee is away from their tax home overnight (or long enough to require sleep) and for a business reason. Commuting, personal side trips, and expenses for a spouse who tags along do not qualify.
If the travel qualifies, you can reimburse transportation (airfare, mileage, rental car), lodging, 50% of meals, and incidental expenses. Note the 50% limit: even when you reimburse 100% of a meal under a per diem, only the meal portion is subject to the 50% deduction limit on your business return under Section 274(n). For 2025-2026 high-low rates, the meal portion is $86 in high-cost areas and $74 elsewhere — that is the amount subject to the 50% cut.
2. Adequate substantiation within a reasonable time
The employee must provide an expense report showing the amount, date, place, and business purpose — generally within 60 days after paying or incurring the expense. For per diem, "amount" is satisfied by the federal rate itself, but the other three elements must still be documented. A calendar entry that says "Chicago, Sept 12-14, client onboarding for Acme Corp" plus the per diem calculation is sufficient. A credit card statement alone is not.
This is where many small businesses stumble. A Slack message that says "spent $400 on food in Chicago" does not substantiate anything. A simple template that captures dates, city, purpose, and rate applied takes two minutes and saves an audit headache.
3. Return of excess within a reasonable time
If you advanced more than was substantiated — for example, you gave a $1,000 advance for a $957 per diem trip — the employee must return the $43 excess within 120 days. The 60-day substantiation and 120-day return windows are the IRS safe harbors; you can set shorter deadlines, but not longer ones, and still have an accountable plan.
Fail any one of these tests and the plan becomes nonaccountable. The entire reimbursement is then treated as wages: you must report it on Form W-2, withhold income and payroll tax, and the employee cannot deduct it elsewhere. For a small employer, that reclassification can be more expensive than the travel itself.
How to Pay It: Practical Mechanics for 2026
Setting the Rate
- Pick one method per employee per year. If you choose high-low for an employee, use it for all of their travel from October through September. You can use GSA detailed rates for another employee, but do not bounce a single employee between methods to cherry-pick higher rates.
- Apply the correct high-low split. On travel days that include both lodging and M&IE, use the full $319 or $225. On partial days or when lodging is not needed, use only the M&IE portion ($86 or $74). On the first and last day of travel, federal guidance limits M&IE to 75% of the daily rate — $64.50 high / $55.50 low for a full M&IE day — to reflect that the traveler is not away for the full day.
- Update your list on October 1. Bookmark the annual IRS notice (Notice 2025-54 for the current year) and the GSA per diem lookup at gsa.gov/travel/plan-book/per-diem-rates. Rates apply based on travel date, not reimbursement date. A trip that starts September 30 and ends October 2 straddles two rate years; apply each year's rate to the days that fall in it.
Documenting Without Drowning
A one-page expense report is enough:
- Employee name, destination, departure and return dates and times
- Business purpose (client name, project, conference)
- Rate method used (e.g., "High-low, high-cost, 3 days x $319")
- Lodging folio if you reimburse lodging at actual cost
- Employee signature and manager approval
Keep these reports for at least three years — the standard IRS record-retention period for substantiation.
Reimbursing Owners and Partners
Per diem under an accountable plan works for employees, including shareholder-employees of a corporation. Sole proprietors, partners, and LLC members taxed as partnerships cannot pay themselves a tax-free per diem; their travel is deducted on Schedule C or Form 1065 as an ordinary business expense at actual cost or using the standard per diem as a substantiation method, but it is not a reimbursement through payroll. If you are an owner-operator, talk to your tax advisor about how to document travel without running it through an accountable plan at all.
The Bookkeeping Difference That Actually Matters
Here is where travel policy meets your books.
With actual expenses, every receipt becomes a line item. That is great for granularity — you can see exactly how much went to airfare versus meals — but it creates classification work. Meals subject to the 50% limit must be separated from lodging and transportation, or your tax return will overstate deductions. A $400 hotel bill that includes a $35 room-service breakfast needs to be split.
With per diem, your books are cleaner but less detailed. A single daily amount covers multiple categories. Best practice is to split the per diem in your accounting system using the IRS meal allocation: for each $319 high-cost day, book $233 to lodging and $86 to meals (50% deductible), and for each $225 standard day, $151 to lodging and $74 to meals. That preserves the correct tax treatment while keeping data entry to one line per day.
Either way, consistency is the audit defense. Pick a method, write it into a one-paragraph travel policy, and apply it uniformly. Auditors do not expect perfection; they expect a reasonable, documented system. A business that sometimes uses per diem, sometimes actuals, and sometimes "we just Venmo'd $200" with no expense report looks like it has no system at all.
Common Mistakes to Avoid
Paying per diem above the federal rate without treating the excess as wages. If you pay $350 per day in a $225 locality, the extra $125 is wages. Withhold tax on it and report it, or lower the rate. "We pay everyone $300 to keep it simple" is simple until it creates W-2c corrections.
Forgetting the 50% meal limit on your own return. Employees are reimbursed 100%, but you deduct only 50% of the meal portion. Many businesses book the entire per diem as "travel expense" and deduct it all. At year-end, your accountant has to untangle it — or the IRS does.
Not requiring the business purpose. The time-place-amount-purpose test applies even to per diem. "Chicago" is not a purpose. "Chicago — final walkthrough for 123 Main St. build, with client" is.
Treating per diem as optional record-keeping. Per diem eliminates the need for meal receipts, not the need for documentation. You must still track where and why someone traveled. A calendar invite and a one-line expense report are enough — but zero documentation is not.
Using per diem for commuting or day trips. Travel must be away from the tax home overnight. A day trip to a client two hours away, no matter how expensive lunch was, does not qualify for tax-free per diem.
A Simple Decision Tree for Your Next Trip
Ask three questions:
- Is the trip overnight and business-related? If no, reimbursements are taxable wages under either method.
- Will you save time by skipping receipt collection? If yes and destinations are predictable, use high-low per diem. If costs are highly variable or you already provide meals/lodging, use actual expenses or a hybrid (actual lodging + M&IE per diem).
- Can you meet the accountable-plan deadlines? If you can get expense reports within 60 days and excess returned within 120 days, you keep reimbursements tax-free. If not, fix the process before you worry about the rate.
Most small businesses with fewer than 50 employees land on a hybrid: actual airfare and lodging (one or two receipts) plus M&IE per diem at the high-low rate. It balances control, simplicity, and audit readiness without overpaying.
Simplify Your Financial Management
Whether you choose per diem or actual expenses, the payoff comes from consistency — a written policy, a one-page expense report, and books that split meals correctly the first time instead of at year-end. Beancount.io gives you plain-text, version-controlled accounting that makes those travel entries transparent and auditable, with no black boxes between your expense reports and your ledger. Your travel policy lives in text, your numbers stay yours, and your audit trail is a git log. Get started for free and keep every trip — and every dollar — easy to explain.