Social Security refers to mandatory contributions (often called social insurance or payroll taxes) paid on employment income to fund public benefits such as pensions, healthcare, maternity pay and sickness benefits.

In most cases, Social Security contributions are due in the country where the work is physically performed. However, rules vary by country, and cross-border employment can create complex compliance requirements.

No. Social Security obligations can apply to short-term business travel, temporary work and Posted Worker activity. Even brief trips may need to be assessed to confirm whether an A1 certificate, Certificate of Coverage or equivalent document is required.

In many cases, yes. Employees travelling internationally for work may need a Certificate of Coverage, depending on the home country, host country, activity type and duration of the trip.

Outside Europe, business travellers may still need a Certificate of Coverage or equivalent document under bilateral Social Security agreements.

An A1 certificate is used for Social Security compliance in a European context. A Certificate of Coverage is commonly used for international travel outside the EU where a bilateral Social Security agreement applies. Both can help confirm where Social Security contributions are due and reduce the risk of double contributions.

Proposed EU reforms may simplify A1 requirements for certain business trips in the future, but the changes are not yet in force and are not expected to apply for some time. Current A1 obligations should still be assessed before travel.

If an A1 certificate or Certificate of Coverage is not obtained when required, both the employer and employee may face compliance risks in the host country. This can include:

• Double Social Security contributions, where contributions are required in both the home and host countries
• Financial penalties and fines from local authorities
• Retroactive contribution liabilities, sometimes going back several years
• Issues during audits or inspections, particularly in countries with strict enforcement.

In addition, without an A1 certificate, employees may lose access to certain benefits or face uncertainty about which Social Security system applies.

Obtaining the correct documentation helps ensure that contributions are paid in the right country and protects both the employee and employer from unnecessary cost and compliance risk.

Nomadic helps organisations manage global Social Security compliance by:

• Assessing whether Social Security obligations apply to each trip
• Automating A1 certificate and Certificate of Coverage applications
• Providing centralised visibility across international travel and assignments

This helps reduce compliance risk and administrative burden for globally mobile employees.