Expatriates or expats are employees that are temporarily sent overseas either temporarily or permanently for international assignment by their company. The word is derived from the Latin terms ex ("out of") and patria ("country, fatherland").

Expatriation of workers involves many factors and risk among them are the need for greater operating unit diversity, more external stakeholder influence, higher levels of risk exposure and more personal insight into employees’ lives and family situations.

To operate internationally, HR must engage in activities not necessary in a domestic environment, mainly activities such as international taxation, international relocation and host government relations by contacting with foreign governments for acquiring work permits, visas etc.
The salary of internationally assigned personnel often consists of standard salary and monetary benefits such as cost of living and non-monetary incentives such as health care, education expenses, and housing. Some companies will even completely cover the cost of expatriate children's education, even at relatively expensive international schools, while other, usually smaller companies, encourage families to find local schooling options.

One of the greatest disadvantage of using expatriates is the possibility of expatriate failure. Expatriate failure occurs when an expatriate returns to her home country prior to finishing her international assignment, or if the expatriate resigns from her job before completing the assignment. Despite adjustment training, there is no guarantee how well an expatriate will adapt and socialize in the new country. Should an expatriate fail to complete their international assignment, a potentially large sum of money could be wasted. This cost includes direct cost which is the salary wasted given to expatriate, usually costs three times the money as a matter of currency, training cost and abroad expenses. Indirect costs such as the damage to international customer relationship may also become an issue.

Being sent on expatriation also involves greater involvement in the personal life of employees chosen for foreign assignments. The HR manager must ensure that the expat fully understands the aspects of the compensation package provided in the foreign posting. Next, the HR manager need to consider the willingness of the employee’s family to relocate, the willingness of the expatriate’s decision to go on an overseas assignment can be greatly affected by the family such as the parents' health, the job of the expatriate’s spouse and the children’s education. After that, the HR department has to support the expat’s family by providing cross-cultural training for them to adjust to the foreign culture, provide a safe lodging and transportation, and to assist in admitting the children to international school in the country they are assigned to.