Staying on top of global tax developments is becoming increasingly complex as governments respond to inflation, workforce mobility, and new ways of working. During our January Global Tax Chat, my colleague Pat Jurgens and I shared key updates from around the world, and with Grace Pursley hosting, we unpacked what they mean for mobility programs in 2026 and beyond.

If you weren’t able to join us live, don’t worry—the session was recorded and is available to watch on demand here. 

Below is a snapshot of the most important global tax developments mobility teams should have on their radar.

Around-the-World Global Tax Updates

India: Court Ruling on Provident Fund Contributions

A recent Indian court ruling has clarified how Provident Fund (PF) contributions and distributions are taxed for international workers. The decision impacts both inbound assignees and Indian nationals on outbound assignments, particularly in how employee and employer contributions are treated when assignments cross borders.

Why it matters:

Mobility teams may need to revisit PF assumptions within cost projections and tax equalization calculations for India-related assignments.

Belgium: Changes to the Expatriate Tax Regime

Belgium continues to refine its expatriate tax regime, with changes affecting eligibility, benefits, and compliance requirements. These updates may alter the net tax position for current and future assignees working in Belgium.

Why it matters:

Program policies and assignment cost estimates may need updating to reflect revised benefits and limitations under the new regime.

OECD: Model Tax Treaty Update on Remote Work

The OECD has updated its Model Tax Convention to provide greater clarity on how remote workers factor into permanent establishment (PE) risk. The update focuses on defining when remote work could create a taxable presence for employers.

Why it matters:

With remote and hybrid work now embedded in many mobility programs, companies should reassess PE risk and ensure alignment between tax, mobility, and workforce strategy teams.

United States: What’s Changing for 2026?

Several U.S. federal tax changes will take effect in 2026, many of which will modestly reduce tax burdens for most taxpayers:

  • Inflation-adjusted tax brackets and standard deductions
  • Higher income phaseout of itemized deductions, impacting taxpayers in the 37% bracket
  • Charitable donation updates
    • Itemizers: deductions allowed only for donations exceeding 0.5% of AGI
    • Non-itemizers: above-the-line deductions up to $1,000 (single) or $2,000 (joint)
  • Children’s savings accounts (“Trump Accounts”)
    • Seed funding available for qualifying children born between January 1, 2025 and December 31, 2028

Why it matters:

These changes can affect hypothetical tax calculations, net-to-gross projections, and overall assignment cost estimates for U.S.-based employees.

Deep Dive: What Is Hypothetical Tax?

Poll Results: How Often Do You Update Hypo Tax for Your Assignees?

Multiple Choice

  • Annually - 52%
  • Once, at the beginning of assignment - 5%
  • When there is a change in salary or family size - 40%
  • We don’t tax-equalize - 12%
  • What is hypo tax? - 9%

During the session, we took a closer look at hypothetical tax (hypo tax)—a foundational concept in tax equalization programs.

At a high level:

  • The employee pays a hypothetical home-country tax as if they had never gone on assignment
  • The company covers actual host-country taxes
  • Optional year-end reconciliations may apply

Despite its importance, many organizations update hypo tax inconsistently—or not at all.

Common approaches include:

  • Annual updates
  • One-time calculations at assignment start
  • Adjustments after salary or family changes
  • No tax equalization at all

Understanding how and when hypo tax is updated is critical for maintaining program equity and cost control.

Looking Ahead

Global tax rules will continue to evolve as governments adapt to new work patterns and economic pressures. Staying informed—and proactive—can help mobility teams manage risk, control costs, and support assignees more effectively.

If you missed the live session, the recording is available here where you can also watch past Global Tax Chats & all of our webinars. Further Global Tax Chats to come in 2026, please subscribe to our blog to receive the invites.

Contact Us

Are you looking for information on global tax rates around the world?

AIRINC’s International Tax Guide contains all of the information you need to support your assignment tax planning — including global tax rates, deductions, and employee/employer social security contributions.

Are you trying to move an employee from a lower- to a higher-tax rate location?

Use AIRINC’s Global Salary Comparison to understand the compensation you would need to offer to cover the difference and make the appropriate offer to your employee.

Want to See Even More on Tax?

Check out our Global Tax Rates Heat Maps — a fun and interactive way to explore how income tax rates compare around the world. These colorful maps make it easy to visualize global differences at a glance and are updated regularly by AIRINC’s research team.