TN 20 (01-12)
RS 02001.267 Detached Worker Rule under the Agreement with Belgium
A. Definition of a detached worker
In the case of employment, under the agreement, a detached worker is an employee whose employer sends him or her from one country to work temporarily in the other country for the same employer or for an affiliate of that employer; or
In the case of self-employment, under the agreement, a detached worker is a self-employed worker who temporarily transfers his or her business from one country to the other country.
B. General rules for detached workers
Under the agreement, a detached worker remains subject only to the social security taxation and coverage laws of the country from which the employer transfers him or her from or the country the worker transfers their self-employment from provided that the worker meet all the following conditions:
The employer or worker expects the period of work in the host country to last no more than five years. The five-year period begins with the date the work in the host country begins or July 1, 1984 (the effective date of the agreement), whichever is later.
The employment relationship (in the case of employment) or the business activity (in the case of self-employment) existed before the worker transfers from the home country; and
If an American employer sends an employee to become an employee of the company’s affiliate in Belgium, the American employer must have entered into an agreement with the Internal Revenue Service (IRS) under section 3121(l) of the IRS Code. The 3121(l) provides social security [recommend using lower case] coverage for U.S. citizens and residents employed by the affiliate. In such cases, the employer must still obtain a certificate of coverage to establish the exemption from Belgian social security taxes.
NOTE: The detached worker rule may apply even if the worker does not go directly from one country to the other but first works in a third country.
C. Related references