Nicoline Nielsen
Consultant, Crossbord | International Tax and Social Security Compliance
Profile
Nicoline Nielsen advises employers on where social security is owed and where an employee is taxed once work crosses a border. This is an area where errors are easy to make: A1 certificates, tax residency assessments, and the payroll alignment that follows, for employees connected to Denmark. Nicoline joined Crossbord as a tax trainee and works within the international mobility team, keeping tax, payroll, and social security consistent as a workforce changes, so a decision in one area does not create a problem in another.
Social security and cross-border compliance
Nicoline’s focus is practical: what is owed, where, and what payroll has to reflect.
- A1 certificates and EU social security coordination. Determining which country’s social security applies for employees working across more than one member state under EU Regulation 883/2004, so contributions are paid in one country rather than two.
- Tax residency and double taxation. Assessing where an employee is tax resident and which obligations follow from an international work arrangement.
- Danish inbound payroll and reporting. Setting up compliant payroll and reporting for foreign employees working in Denmark.
- Payroll and compliance alignment. Making sure payroll reflects the underlying tax and social security position, not just a headline salary.
Get to know Nicoline: her background, interests, and path to Crossbord
Specialisation
Nicoline’s work sits at the intersection of several compliance obligations that are often handled in isolation but need to be coordinated:
EU social security coordination
A1 certificate applications and ongoing coordination under EU Regulation 883/2004, including employees with multi-country work patterns and cases where the applicable legislation is unclear.
Tax residency and double taxation
Assessment of where employees are tax-resident, how double taxation agreements (DTAs) apply, and what that means for withholding and reporting obligations in Denmark and the employee’s home country.
Danish inbound taxation
Cross-border setups for foreign employees working in Denmark, including applicable tax schemes, reporting obligations to SKAT, and coordination with the Danish inbound expat tax regime (forskerskatteordningen) where relevant.
Payroll and compliance alignment
Connecting payroll processes with the underlying tax and social security position, so that what is reported reflects what is legally required rather than what the payroll system defaults to.
Her focus is on making complex rules operational: compliant, accurate, and sustainable to run.
Representative work
- Coordinated A1 coverage for employees working across several EU countries, establishing correct social security positioning under EU Regulation 883/2004
- Supported Danish inbound employee setups with aligned tax, payroll, and reporting structures
- Managed year-end reconciliation for employees with income split across jurisdictions
- Identified and resolved compliance gaps in international payroll setups
Sector experience
Nicoline has worked on Crossbord engagements across:
- Engineering and construction
- Production and manufacturing
- Shipping and offshore
- Corporate and office-based roles
Global experience
Countries worked with:
| Region | Countries |
| Europe | Denmark · Netherlands · France · Germany · Italy · Poland · Romania · Lithuania · Latvia · Croatia · Norway · Sweden |
| Other | United Kingdom · United States |
Education and languages
Education
Master of Science (MSc) in Business Law, Aalborg University, 2024
Languages
- Danish
- English
Get expert support with cross-border compliance in Denmark
Crossbord supports companies in managing A1 certification, tax residency assessments, and cross-border compliance obligations linked to Denmark.
By combining tax, payroll, and social security into one coordinated solution, Crossbord helps organisations reduce complexity, strengthen compliance, and manage internationally mobile employees with confidence.