Tax Equalization vs. Tax Protection for Global Mobility

Which tax policy is right for your assignment population?

Should an employee benefit from lower local taxes when assigned to Singapore? And who should bear the additional tax burden when an employee is assigned to Germany or the United States?

These questions lie at the heart of the decision between Tax Equalization and Tax Protection. Both approaches are designed to protect employees from a higher tax burden resulting from an international assignment, whether as part of a short-term or long-term assignment. The key difference lies in how potential tax savings are treated.

While the distinction may appear straightforward at first glance, the practical implications can be significant.

What Is Tax Equalization?

Under a Tax Equalization policy, the employee should be neither better nor worse off from a tax perspective than if the assignment had never taken place. To achieve this, a hypothetical tax, commonly referred to as hypotax, is calculated based on the employee’s stay-at-home compensation and is typically withheld from payroll on a monthly basis.

In return, the employer assumes responsibility for the actual taxes covered under the tax equalization policy in the host country and, where applicable, for assignment-related taxes in the home country. The employer therefore generally bears the additional cost when actual taxes are higher than the hypotax, but also benefits when they are lower.

Tax Equalization in one sentence
The employee pays a hypothetical home-country tax, while the employer covers the actual taxes in the home and host countries.

What Is Tax Protection?

Under a Tax Protection policy, the employee’s actual taxes on income covered by the policy are compared with the taxes they would have paid at home. If the actual taxes are higher, the employer generally covers the difference. If they are lower, the employee keeps the tax benefit.

Unlike under Tax Equalization, no ongoing hypotax is generally withheld. The employee remains responsible for paying their actual taxes, while the employer reimburses any additional tax covered by the policy.

Tax Protection in one sentence
Tax Protection protects employees from a higher tax burden resulting from an international assignment, while any tax benefits generally remain with the employee.

Practical Example A: Assignment from Zurich to Munich

Tax Equalization Scenario:

Under a Tax Equalization policy, the employee bears the hypothetical tax burden of CHF 35’000, while the employer pays the actual tax liability of CHF 70’000. In this simplified example, the employer therefore bears the difference of CHF 35’000.

Tax Protection Scenario:

The actual tax liability of CHF 70’000 is compared with the hypothetical Swiss tax liability of CHF 35’000. The employer reimburses the difference of CHF 35’000, leaving the employee with a tax burden of CHF 35’000.

Practical Example B: Assignment from Zurich to Singapore

Tax Equalization Scenario:

Under a Tax Equalization policy, the employee bears the hypothetical tax liability of CHF 35’000. The employer pays the actual tax liability of CHF 20’000. The resulting tax benefit remains with the employer.

Tax Protection Scenario:

The actual tax liability of CHF 20’000 is compared with the hypothetical Swiss tax liability of CHF 35’000.
As the actual tax liability is lower, the resulting tax benefit of CHF 15’000 remains with the employee.

The Overlooked Cost Driver: Tax Gross-Up

When an employer pays an employee’s personal tax liability or reimburses additional taxes resulting from an international assignment, the payment itself will generally be taxable. If the employer also covers the tax due on this additional benefit, this creates a tax-on-tax effect. The final amount therefore needs to be calculated taking into account the applicable local tax rules.

Simplified Illustration
Assuming a constant marginal tax rate of 40%, a net employer benefit of CHF 50’000 results in a gross amount of: CHF 50’000 ÷ (1 − 40%) = CHF 83’333.
The difference of CHF 33’333 illustrates the tax-on-tax effect. In practice, the calculation may also need to reflect progressive tax rates, deductions and additional levies.

At first glance, Tax Equalization may seem like the more cost-effective option for employers when taxes in the host country are lower than at home. However, tax gross-ups and additional administration can reduce some of these savings. Which approach works best will ultimately depend on the individual assignment and should be considered when designing the assignment policy.

Tax Reconciliation: The Final Settlement

Whether a company applies Tax Equalization or Tax Protection, a final reconciliation is generally required once the relevant tax information is available. This typically takes place after the end of the tax year or once the relevant tax assessments have been issued.

Tax Equalization

Under a Tax Equalization policy, the reconciliation process is typically used to:

Compare the hypotax withheld with the final hypotax liability
Reflect bonuses, variable compensation and equity awards
Allocate compensation between the home and host country
Determine any additional payments or refunds

Tax Protection

Tax Protection also requires a final comparison between the actual tax liability and the hypothetical home-country tax liability. If the actual tax is higher, the employer covers the agreed difference. If it is lower, the employee typically keeps the resulting tax benefit.

Tax Equalization and Tax Protection Compared

Conclusion

Tax Equalization provides employees with a broadly comparable personal tax burden regardless of where they are assigned, while Tax Protection allows them to benefit from potential tax savings during an international assignment.

There is no single approach that works best for every company. The right choice will depend on the company’s objectives, its mobile workforce and how its global mobility programme is managed. What matters is that the chosen approach is clearly defined and applied consistently. This includes setting out which compensation and taxes are covered, how hypothetical tax is calculated and how any additional payments or refunds are dealt with.

Successful implementation also depends on good coordination between Global Mobility, Payroll, HR and tax advisors. Clear responsibilities, reliable processes and transparent communication with employees help ensure that the chosen approach works effectively in practice.

How We Can Help

Choosing the right approach is only the first step. Our Global Mobility specialists can support you with the design, calculation and implementation of Tax Equalization and Tax Protection policies, as well as the related tax compliance requirements. This includes:•