As a general rule, a posted worker from the EEA or Switzerland remains part of their home country’s social security system. To certify this, a valid certificate of coverage document (A1 form) has to be applied by the employer from the competent social security authority of that country. The A1 certificate certifies which legislation applies to the employment contract in accordance with Regulation (EC) No 883/2004 of the European Parliament and of the Council of 29 April 2004 on the coordination of social security systems.
In general, third country national employees with third county registered employers remain in the social security system of their home countries, if the posting employment does not exceed two years and if the Netherlands has a bilateral agreement on social security with the home country of the posted employee that provides an exemption. In order to prove coverage in the foreign country, the individuals should obtain a Certificate of Coverage from the competent social security authority for the period of their activity on Dutch soil.