Global Mobility Tax Equalization Cost Calculator
Tax equalization keeps the assignee neutral but it can double employer cost when sending US assignees to high-tax countries. Calculate gross-up cost before approving the assignment.
| Assignee total comp (base + bonus + allowances) | — |
| Hypothetical tax (deducted from assignee) | — |
| Actual host tax (paid by employer) | — |
| Gross-up: tax on tax assistance | — |
| Tax prep + advisory fees | — |
| Host employer social charges | — |
| Total annual employer cost | — |
| Cost as multiple of base salary | — |
Tax equalization is the dominant expatriate compensation policy — the employer ensures the assignee pays the same effective tax they would have paid at home (hypothetical tax) regardless of where they’re sent. The employer absorbs the difference between hypothetical and actual host tax, plus the gross-up on that tax assistance (because tax assistance is itself taxable). For US assignees to high-tax countries (Germany, UK, Nordics), the total employer cost commonly runs 2.5-3.5x base salary in the first year.
How Tax Equalization Actually Works
The mechanics: payroll deducts a hypothetical tax from the assignee’s paycheck — calculated as what they would have paid in their home country on the same comp. The employer then pays the actual host tax directly to the host tax authority. If actual is higher than hypothetical (almost always for US → Europe), the employer bears the difference. The catch: tax assistance is itself taxable compensation in the host country, requiring an additional gross-up. In a 50% bracket, every $1 of tax assistance costs the employer $2 ($1 to the tax authority, $1 to gross up the assistance). This is why equalization to Nordic countries balloons costs so fast.
Lower-Cost Alternatives to Consider First
(1) Tax protection: assignee benefits if host tax is lower (Singapore, Hong Kong, Switzerland); pays own tax if higher. Lower employer cost when destination is lower-tax. (2) Localization: assignee becomes a local employee with local comp package — no equalization, no gross-up. Best for long-term assignments (3+ years) and for moves to low-tax destinations. (3) Short-term assignment: under 183 days in host country usually avoids host tax residency (subject to treaty). Best for project work. (4) Virtual assignment: no physical relocation — the assignee works remotely from home country for host-country team. Zero equalization cost. (5) Commuter assignment: weekly travel, primary residence stays in home country.
Last updated May 2026. Sources: Mercer Global Mobility, KPMG Global Tax.