Cross-border employment: is your social security in order? Do the end-of-year check

What exactly is cross-border employment?

A cross-border worker lives in a neighbouring country and works in Belgium, or vice versa. The following principles apply:

• Labour law: The legislation of the country where the work is usually carried out applies, unless the parties have chosen a different jurisdiction.

• Social security: In principle, the country of employment principle applies. Social security contributions are paid in the country where the work is physically performed.

• Taxation: Taxes are generally levied in the country of employment.

With the rise of teleworking, it is important to monitor the distribution of working hours between countries closely. If a cross-border worker works both at home and in the neighbouring country, this may have consequences for the applicable social security regime.

Teleworking: points to consider for social security

Telework: key points for social security

An employee who works partly in the employer’s country and partly from home in their country of residence is engaged in “simultaneous employment”. This has a direct impact on the social security rules that apply.

Since the rise of telework after Covid, the European social security authorities have established specific rules in a framework agreement on telework, applicable since 1 July 2023. This framework agreement was signed by Belgium and its neighbouring countries (the Netherlands, France, Germany and Luxembourg).

More specifically, the framework agreement provides that:

Employees may perform up to 49.9% of their working time as telework in their country of residence while remaining subject to the employer’s social security system (i.e. the system of the country where the employer’s registered office is located), provided that:

• A joint application has been submitted (A1 certificate);

• The employee performs telework exclusively in the state of residence;

• The employee does not carry out any self-employed activity;

• Both countries have signed the agreement.

Important: More than 49.9% telework? In principle, the employee will then be subject to the social security system of their country of residence.

Why do this end-of-year check now?

The end of the year is the perfect moment to review the work schedules of cross-border employees. Telework percentages determine the applicable social security regime, and failing to check in time can result in unexpected (double) contributions in the country of residence, penalties, late-payment interest and reputational damage.

Checklist for employers

• Verify the teleworking percentage for each employee.

• Check whether activities other than teleworking were carried out in the country of residence (e.g. client visits).

• Confirm that A1 documents have been requested correctly.

Conclusion

Cross-border employment requires careful monitoring, especially in a hybrid work situation. Taking action now will help you avoid unpleasant surprises in 2026.

Is this a new topic for you and would you like some guidance? Or are you already familiar with the subject but still have practical or legal questions? Feel free to contact us at contact@vdl.be, or fill in the contact form below.