Key Considerations for Supporting Mobile Employees on International Assignments

An offer to take on an international assignment is often seen by employees as both a vote of confidence from their employer and a valuable opportunity for career growth. Though both are true, it’s also important to look beyond the professional benefits and consider the logistical, financial, and regulatory implications involved—particularly around immigration, tax compliance, and compensation across both the Home and Host countries.

Below are some of the key questions an employee should ask of their employer to better understand the support available and prepare for the various complexities of an international assignment.

What kind of mobility support will be provided?

Mobile employees often face a range of regulatory challenges tied to their international move, including potential immigration and tax-related requirements for themselves and any accompanying family members. It’s important for them to understand whether their employer will provide assistance with these issues, or if the employee will need to manage them independently.

Companies that regularly assign employees internationally often have programs in place to help navigate immigration requirements in the Host country and manage tax obligations in both the Home and Host locations. However, not all companies offer this level of support. If mobility support is limited or unavailable, employees should seek clarity from their employer on what assistance, if any, will be provided. For example, if no tax assistance is offered, it’s critical for the employee to connect with a global mobility tax professional before the move to understand their potential obligations and stay compliant with relevant laws and regulations. Failing to do so could lead to unexpected tax bills or legal complications.

Employees should also ask whether the company’s support will extend beyond the relocation itself. Tax and residency issues can emerge months or even years after arrival in the Host country, making ongoing guidance just as important as initial support.

Key questions to consider from a tax perspective:

• Will the company provide ongoing support after the employee is established in the Host country, or is assistance limited to the initial relocation period?
• If the employee’s income becomes subject to a higher tax rate in the Host location, will the company address this through gross-ups or a tax equalization policy to maintain a neutral tax position?
• If the employee’s spouse is eligible to work in the Host location or is required to file taxes separately, how will those wages be treated under the company’s mobility policies, and will any compliance support be extended to the spouse?

Supporting mobile employees with their US tax obligations is critical for a successful international assignment. Download our eBook, "US Taxation at a Glance: Important US Tax Information for Expatriates and Foreign Nationals," for a high-level overview of key US tax considerations, including income reporting, disclosure requirements, and vital documentation.

Will the employee be subject to tax in the Host country for income or social tax purposes?

In many cases, mobile employees may become subject to Host country income and/or social tax obligations from their first day of work in the new location. That’s why it’s critical for HR and mobility teams to understand the Host country’s tax rules in advance and clearly communicate them to the employee.

Both the company and employee should be aware of the domestic requirements for registering with tax authorities (e.g., obtaining a tax identification number), reporting income, making tax payments (such as withholding or estimated payments), and filing income tax returns. Additionally, income tax treaties and totalization agreements (which govern social security coordination between countries) may be available to reduce or eliminate double taxation and simplify compliance.

While many tax treaties include provisions that exempt income from Host country taxation for temporary assignments—often based on the “183-day rule”—this exemption only applies if several specific conditions are met. These conditions can vary significantly depending on the Home and Host country combination. Furthermore, even if a treaty exemption applies to income tax, it typically does not extend to other forms of taxation, such as social security.

Because of the complexity involved in applying treaty and domestic tax rules, HR and mobility managers should not expect employees to navigate these requirements alone. It’s important to consult with internal resources or engage a global mobility tax professional to assess the specific tax treatment and determine what support the company will provide to help employees remain compliant and address any incremental tax burdens.

What are the company’s compensation and benefits policies for international employees?

It’s important for companies to help mobile employees understand the potential incremental costs associated with an international assignment—and how the company’s policies will address those costs. While some expenses, like housing and relocation, may be obvious, others—such as differences in the cost of goods, transportation, or education for children—may require closer review and planning.

Many organizations structure compensation packages to help employees maintain their standard of living while on assignment. This can involve working with a mobility services provider to assess and compare the cost differences between the Home and Host locations. As referenced earlier, tax differences can also affect an employee’s take-home pay. To address this, many companies implement tax reimbursement policies—such as tax equalization—to help offset increased tax liabilities in the Host location.

Some companies may distinguish between employer-initiated assignments and employee-requested moves. In the latter case, support for incremental costs or tax equalization may be limited or unavailable, which increases the importance of the employee obtaining professional guidance before making the move.

In some cases, an international move involves a formal change in employment status, with the employee transitioning from the Home country entity to the Host country subsidiary. This change can significantly impact benefits, as the Host entity may offer different healthcare, insurance, or retirement plans. It may also result in a loss of accrued benefits from the Home employer.

It’s important for HR and mobility teams to clearly communicate which benefits will continue while the employee is abroad, and to outline any Home or Host country implications. For instance, there may be tax consequences if the employee continues participating in the Home country pension plan, or if they are required to participate in a Host country plan. If a reduction in benefits is expected, companies may want to consider offering negotiated adjustments to help offset the impact and maintain employee satisfaction.

Supporting success for mobile employees

Companies play a vital role in helping employees navigate the many complexities associated with working abroad. From tax and immigration requirements to compensation, benefits, and long-term planning, there are many areas where clear communication and proactive support can make a significant difference in the success of a global assignment.

By addressing the questions outlined in this article—and by providing consistent support throughout the entire lifecycle of the assignment—HR and mobility teams can help employees feel confident, informed, and supported. This not only reduces compliance risks and unexpected costs but also contributes to a more positive and productive international experience for the employee and their family.

Need help navigating the complexities of international assignments? Contact us today to learn how we can support your global mobility program and prepare your employees for their assignments abroad.