Multi-State employment : self-employment in multiple countries

The Social Security legislation of the worker’s State of residence will apply if a substantial part of their work is carried out in their State of residence.

Otherwise, the legislation of the State where the self-employed worker engages in their main occupation will apply.
Substantial work amounts to 25 % of total work carried out. For self-employed workers, this is assessed against their turnover, their working hours, their number of services performed, or their income.
The concept of main occupation is assessed with regard to the worker’s fixed and permanent head office and the ongoing nation or duration of their work.