Per diem (Latin for "per day") is a fixed daily allowance employers pay to cover meals, lodging, and incidental expenses during business travel. Navan automates per diem by connecting daily allowances to trip itineraries, replacing the manual process of collecting receipts for every coffee and cab ride with a flat rate based on destination.
The concept serves two purposes: it simplifies expense administration for finance teams, and it gives travelers predictable spending power without the friction of collecting and submitting receipts for small purchases.
In the United States, the General Services Administration (GSA) publishes official per diem rates annually, typically in mid-August, for the upcoming federal fiscal year starting October 1. These rates cover two components:
While GSA rates are mandatory for federal employees, private-sector companies are free to set their own per diem policies. Many use GSA rates as a benchmark because they're defensible, well-researched, and automatically satisfy IRS accountable plan requirements.
Travelers typically receive 75% of the M&IE rate on travel days (the day of departure and the day of return) and the full rate on days spent entirely at the destination. This partial-day calculation is one of the most common sources of confusion — and manual error — in per diem administration.
Companies choose between two reimbursement approaches:
Per diem trades granularity for efficiency. A company using per diem won't know whether an employee spent $15 or $75 on dinner — it only knows the daily allowance was paid. Actual expense reimbursement provides that granularity but at the cost of 71% of travelers spending 30+ minutes per expense report .
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Automate travel and expense management in one platform.Per diem payments are tax-free for employees and deductible for employers, but only when structured as an IRS "accountable plan." The three requirements:
If per diem exceeds GSA rates, the excess is treated as taxable income. If the arrangement doesn't meet accountable plan rules, the entire per diem amount becomes taxable wages — a common trap for companies that pay per diem informally without proper documentation.
The U.S. State Department publishes separate per diem rates for foreign locations, updated monthly. These rates account for local cost of living, exchange rate fluctuations, and seasonal price changes. A business traveler in Tokyo faces a different M&IE rate than one in rural India, and the gap can be dramatic.
For companies with global travel programs, managing per diem across dozens of countries with different rate sources, currencies, and tax rules is a significant administrative burden. Navan automates this by matching itinerary destinations to the applicable per diem rate automatically, including the first-and-last-day partial calculation.
GSA rates are based on hotel survey averages, which means they can lag behind reality in cities experiencing rapid price inflation. Travelers to cities where events, conferences, or seasonal demand spike hotel prices often find the per diem lodging cap insufficient — forcing them to either pay the difference out of pocket or book inconvenient locations farther from the business destination.
The incidentals portion of M&IE (tips, baggage fees, transit costs) was unchanged in the federal system for over two decades before a 2025 increase from $17.30 to $25. Private companies benchmarking against GSA should evaluate whether federal rates reflect actual costs in their employees' most common destinations. Companies using Navan's business travel platform can set custom per diem rates by destination and have them enforced automatically.
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