Not All Per Diem Data Is Created Equal: Why Public Sources Fall Short for Corporate Use

Per diem can be one of the most effective ways to simplify travel expense management. It reduces administrative burden, improves consistency, and helps organizations scale their travel programs more efficiently.

But there is an important catch: per diem is only as effective as the data behind it.

Many organizations rely on public per diem sources as a starting point. Common examples include GSA CONUS rates for U.S. cities, DoD OCONUS rates for Alaska, Hawaii, and U.S. territories, and U.S. State Department rates for international travel. These sources are widely used and easy to access, which makes them appealing for organizations looking for a straightforward reimbursement framework.

The challenge is that these datasets were not built for corporate travel programs.

For organizations managing travel across multiple markets, business units, and employee populations, public per diem tables can create inconsistencies that make policy administration harder, not easier. What appears simple on the surface can quickly become difficult to manage in practice.

Why public per diem sources fall short for corporate use

1. They are not designed for corporate travel realities

Government per diem rates are designed to reimburse federal employees. That purpose matters.

Private-sector travel programs often need to reflect a different set of priorities, including internal travel policies, negotiated supplier arrangements, traveler expectations, safety considerations, and budgeting requirements. Companies may also need to account for differences in traveler profiles, trip purpose, and regional operating conditions.

As a result, public rates do not always align with what corporate travelers actually experience or what organizations need their policies to support.

2. They lack global consistency

One of the biggest issues for multinational organizations is that public per diem data is not built from a single, harmonized methodology.

When companies rely on a mix of per diem data sources, they are effectively pulling from separate systems with different assumptions, structures, and update cycles. That can lead to inconsistent treatment across locations and added confusion for employees traveling between regions.

It also creates extra work for payroll, finance, and mobility teams that must interpret and validate rates coming from multiple public sources. Instead of supporting simplification, the process can become more fragmented.

3. They may not reflect actual corporate travel patterns

Public rates are credible, but they are not always realistic for business travel decision-making.

Government or publicly available per diem rates can be shaped by factors that do not directly mirror corporate travel behavior, including procurement structures, location-specific anomalies, and other public-sector reimbursement considerations. In some locations, rates may feel too high. In others, they may be too low. In still others, they may simply fail to reflect the conditions travelers are encountering on the ground.

This can be especially problematic in high-cost international markets, secondary cities, or destinations with strong seasonal price swings.

What companies need instead

If per diem is going to support efficiency, fairness, and cost control, organizations need more than a patchwork of public tables. They need a single source of truth that works consistently across their travel program.

That means using data that is globally aligned, locally relevant, regularly updated, and flexible enough to support corporate policy needs.

The AIRINC advantage: a centralized approach to per diem data

AIRINC helps organizations move beyond fragmented public sources by providing a more consistent and corporate-ready foundation for per diem decision-making.

Globally consistent methodology

AIRINC uses a consistent research methodology across more than 2,400 locations worldwide. This helps organizations apply policy more evenly across markets, support equitable treatment of employees, and improve consistency across global travel and mobility programs.

For companies trying to avoid a U.S.-centric approach layered onto a separate global framework, that consistency matters.

Locally collected, highly accurate data

AIRINC’s in-house trained researchers collect price data in the field for lodging, meals, transportation, and goods and services. That produces location-specific data based on what travelers are likely to encounter in the market.

Rather than relying on reimbursement schedules designed for government use, organizations can make decisions based on data that better reflects corporate travel realities.

Quarterly updates

Travel costs do not stand still. Inflation, currency movement, and market volatility can change conditions quickly.

AIRINC’s quarterly updates help organizations work with more current data, giving finance, procurement, and mobility teams a stronger foundation for budgeting, forecasting, and policy management.

Flexibility for organizational needs

Corporate travel policies are rarely one-size-fits-all. AIRINC per diem data can support different travel policy tiers, industry expectations, budgeting goals, and regional travel patterns.

That makes it easier for organizations to build a per diem approach that aligns with their own program design rather than trying to force policy decisions around the limitations of public datasets.

Currency options that reduce confusion

AIRINC delivers rates in local currencies, USD, and other corporate base currencies. For organizations managing travel across multiple locations, this helps reduce confusion, simplify administration, and minimize the risk of payroll or reimbursement errors.

Bottom line

Per diem can save time, reduce friction, and improve the employee experience. But the quality of the outcomes depends on the quality of the data.

Public per diem sources may be useful reference points, but they were not designed to meet the needs of complex corporate travel programs. For organizations looking to build a scalable, reliable, and globally consistent approach, a more purpose-built data source is essential.

AIRINC gives companies the foundation to make per diem work the way it should: efficiently, accurately, and consistently across the organization.