Nicoline Nielsen
Consultant, CrossbordInternational Tax and Social Security Compliance
Profile
Nicoline Nielsen is a Consultant at Crossbord specialising in cross-border tax and social security compliance for internationally mobile employees connected to Denmark.
Companies engage her when they need clarity and structure around obligations that span jurisdictions: where payroll reporting, tax residency, and social security coverage overlap, and where getting the alignment wrong creates downstream risk.
Her work is grounded in execution as much as analysis. Understanding the rules is the starting point. Implementing them in a way that holds up in practice is where the value lies.
When to engage Nicoline
Clients typically work with Nicoline when they are dealing with:
- A1 certificates and social security positioning: determining the correct social security coverage for employees working across EU borders, including multi-country work patterns governed by EU Regulation 883/2004
- Tax residency questions: assessing exposure and obligations for employees working in more than one jurisdiction
- Danish inbound employment setups: establishing compliant structures for foreign employees entering Denmark, with aligned tax, payroll, and reporting from the outset
- Payroll and compliance mismatches: identifying and resolving gaps between what is being reported in payroll and what is required under tax and social security rules
- Year-end reconciliation: managing employees with income split across jurisdictions at year-end, ensuring accurate filings across each relevant country
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
- Expat and globally mobile employee programmes
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
About Nicoline
Who are you?
Many describe me as an old lady trapped in a young woman’s body. I am a bit of a book worm, or maybe more of a book hoarder and reader where I sometimes (most often) have more books on my shelves than I can possibly read in a lifetime. I also love knitting and crocheting.
What do you do at Crossbord?
At Crossbord I am a consultant. Together with the rest of the team I help our clients solve their tax related problems or predicaments.
How did you find your way to Crossbord?
I started as a tax trainee when I was a student. After having finished my studies, I continued at Crossbord and have been here ever since.
What do you love most about your job?
I have the pleasure of having great colleagues, and many great laughs in my daily work life. Having great people surrounding you together with solving (real) peoples’ problem makes everyday quite unique and interesting.
When do you feel successful at work?
When I have solved either a complex issue or having solves an issue for a client which has been (or felt like) a very big issue for them. Giving them the solution or having solved it, feels great!
Tell us a fun or surprising fact about you?
I have played and completed Final Fantasy 10 more than 10 times… and I still cry at every ending.
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.