Providing top contract management and payroll services for over 25 years.

Check out our specialised services for:

About Us

Yellowstone International is your go-to partner for payroll services and contract management. Our nineteen professionals have been in the business for more than 20 years. This makes us the leader in payrolling in the Netherlands. To stay on top of our game we make sure that we always keep abreast of the applicable laws and compliance regulations. But we can’t do it alone – we rely on our extensive (inter) national network of professionals. We take over your chores as a legal employer, arranging for payments and protecting you, as the recipient company, against liability in legal and tax terms. But we also take care of anything related to work permits, immigration and relocation issues. We handle applications for visas, help with the legalisation of documents and find suitable accommodation. And if necessary, we help expats settle in by opening bank accounts, or registering them with their new city of residence and healthcare institutions. We like to contribute to finding the best solution. We like short lines of communication and a personal approach.

We’re here to help. Whether you are an intermediary, a recipient company, employee, or self-employed contractor!

Please contact us;  we will be happy to inform you about the numerous ways in which Yellowstone could make life easier for you!

Phone number

Our team

Antoinette Willems


chief executive officer
Karel Verhagen


Tax, Legal & Compliance
Stefano Buffoli

Stefano Buffoli

chief financial officer
Paul van Berlo

Paul Van Berlo

Senior Account Manager Payroll

Joep van Hout

Junior Account Manager Payroll

Pront Aronson

Senior Account Manager External
Rob Marcelissen

Rob Marcelissen

Rob Beckers

Donny Janssen




Nesli Yuzer


Olga Bastiaansen


Natasja Wajon

Communication / Social Media / Events

Marian de Jong

Lisette van der Steen

Lisette van der Steen


If you are an end client you have come to the right address. We provide payroll and contract management services in the Netherlands, including related HRM services.  We offer the best solution to any personnel issues you may have.

We make every effort to lighten your load. This means you can focus on your core business without having to worry about social contribution payments or taxes, sickness protocols (under the Eligibility for Permanent Incapacity Benefit (Restrictions) Act), continued payment of salary during annual leave or other special tax or employment law issues.

Or maybe you’d like to hire or borrow foreign workers and do not want to get drowned in migration laws and regulations. But of course you want everything to be done properly and above board.

Let’s list the advantages:

  • No complex administrative hassle. Yellowstone will keep all personnel and salary records for you.
  • Eliminate the risks of being an employer: Right from the start you will know what your salary costs are. You don’t have to pay the costs of continued payment in case of absence (due to sickness or inability to work) and don’t have to pay severance.
  • Flexibility: It is fairly easy to let people go, and equally easy to hire temporary workers for projects.
  • Work by the rules.

If you hire workers or independent contractors on a regular basis, from inside or outside the Netherlands, it is important that you are compliant. This means that you comply with the applicable laws and regulations. Our NEN-certification, our quarterly audit opinions, G-account and last but not least our experience of 22 years are guarantees that your company will hire people by the book.

How about the law?

As you will know, the rules change all the time. We make sure that we keep abreast of the latest laws by continuously updating our knowledge. Laws that take effect in the morning we will implement in the afternoon of that very same day. Our extensive (inter)national network of professionals allows us to change gears instantly.  We take care of the legal nitty gritty so you don’t have to. Simple as that.

But what about liability?

It goes without saying that we will ensure that all liability risks will be excluded. Examples are the WAB (Balanced Labour Market Act), the Assessment of Employment Relationships (Deregulation) Act, and the Work and Security Act. And the same goes for the Wages and Salaries Tax and National Insurance Contributions (Liability of Subcontractors) Act and the Eligibility for Permanent Incapacity Benefit (Restrictions) Act). If you hire personnel through us, you need not concern yourself with any of these.

NEN-certified 4400-1

Yellowstone is registered with the Labour Standards Foundation (SNA) as a NEN 4400-1 certified company. More information about this can be found here.

If you use our payroll services, your workers will be in Yellowstone’s employment. We are their employer on paper, take care of the payroll records and assume the bulk of your responsibilities. For instance: you need not continue paying salary to sick employees and we keep leave records.

We will also make sure that you as (end user) client will never have to face additional tax assessments and penalties. We rule out all liability risks for social insurance contributions and tax payments. In addition, we will assume responsibility for all attendant risks, such as the costs related to invalidity.

Your Responsibilities

You select your workers, and you determine their terms of employment. You are also responsible for managing your workers, as they will be working under your direction and supervision.

Our Responsibilities

Yellowstone will:

  • Pay net wages
  • Issue payslips
  • Provide periodical salary statements to agencies
  • Arrange and pay for insurance under the Sickness Benefits Act, Unemployment Act and General Invalidity Benefits Act
  • Enforce the Eligibility for Permanent Incapacity Benefit (Restrictions) Act
  • Continue salary payments in case of disability
  • File notifications of sickness and of recovery
  • Keep leave records
  • Liaise with the occupational health and safety service
  • Arrange for collective insurance
  • Deal with dismissals
  • Implement legislative changes relating to human resources

Please contact us if you would like to know more about the services we provide.

Payroll Services: This Is How It Works

Together we decide which responsibilities we will take over from you. We then record the details in an agreement. You can hire us to provide several HRM services, such as keeping your personnel files or writing a personnel handbook. You will pay us an all-inclusive fee, for which we will send you monthly invoices. Out of this fee we will pay the salaries and make other payments.

Yellowstone’s contract management will help you minimise the risks of hiring freelancers. We will draft and oversee watertight contracts and monitor running contracts. In this way we can avoid problems with social insurance contributions, taxes, the Flexibility and Security Act and the National Insurance Contributions (Liability of Subcontractors) Act.

Contract Management: This Is How It Works

We will screen the company with which you want to enter into a contract. Further to our screening we will determine the risk profile, together with you. If the risk profile does not provide the certainty you need, we will perform a more expansive compliance check. We will also keep the contracts made under the Flexibility and Security Act to avoid that employment relationships arise. We handle invoices and payments, and lastly, we check the compliance certificate.

Compliance Certificate

This is the accountant’s statement about the company’s financial status. This statement might contain a description of payment performance regarding taxes and social insurance contributions. Every quarter we ask the company supplying your workers for a certificate. Whenever the certificate shows that the company cannot offer security, we advise that payments be made to the Tax Authorities directly. This is how your company will be protected against claims for recipients’ liability.


The Tax Authorities may consider the hiring of freelancers as a notional employment relationship. This means that you would still have to pay taxes and insurance contributions for those freelancers. Hiring independent freelancers through Yellowstone eliminates those risks. We check everything and arrange for payments to agencies where necessary.

Together with you we will put together a service package tailored to your exact demands.

Just a random selection:

  • Outsourcing
  • Payroll records
  • Strategic HR partnership
  • Registration and application of collective bargaining agreements
  • Writing a personnel handbook
  • Drafting employment agreements, car expense and tuition assistance schemes
  • Relocation services, such as arranging for work permits and housing of foreign workers

Feel free to contact us if you would like more information about the services we can provide.


What Payroll services can do for you as an agency …

Of course you want to have everything properly arranged for the contractor you have recruited and selected.  Yellowstone believes that providing payroll services means taking over all the complex matters employers face. We hire contractors and pay their salaries. The employment contracts that we offer give contractors the same rights and obligations that apply at your (end) clients. This means that the same remuneration structure applies, including all provisions of the applicable collective bargaining agreement. We make sure that everything is done by the book. You will not regret introducing us to your client.

NEN-certified 4400-1

Yellowstone is registered with the Labour Standards Foundation (SNA) as a NEN 4400-1 certified company. More information about this can be found here.

About the contractors…

If we put contractors on our payroll, they are in Yellowstone’s employment. We handle the payroll accounting and pay the employees. But we take care of other things, too, like:

  • Continued payment of salary during incapacity for work,
  • All the necessary insurance policies,
  • All the necessary work and residence permits,
  • Dismissal cases,
  • Legislative amendments, where applicable,
  • Matters relating to the Eligibility for Permanent Incapacity Benefit (Restrictions) Act


  • You can always contact us if you have questions,
  • We go and see every contractor personally on the work floor.

When you start working for us, you should not only know what contractmanagment is exactly, but also what it means for you: the recipient company allocates you, possibly through a recruitment and selection agency, and the recipient company manages you. In terms of employment law we are the ones hiring you, and then providing you to the recipient company. Therefore, we are your employer, and handle the contractmanagment accounts on the instructions of the organisation for which you work. You can rest assured that your salary will be paid correctly and in time.

Every month…

You submit your time sheets to (or screenshots or copies of the hours that have been approved online) unless the recipient company or agency have other procedures. Before you can submit the timesheets, they should be approved and signed by your manager or agency. You will receive an automatic acknowledgment of receipt.

We will then invoice those hours to the agency. You will get paid once our invoice has been paid, after 5 or after 14 days. You can find the payment terms that apply to you in our online portal. Alternatively, you can use our pre-financing option. If you have any questions, please contact one of our account managers.


Click here for the Timesheet (XLSX)

Payroll contractors are entitled to the same number of days’ leave and any reduction of hours as the recipient company’s permanent staff. If you would like to take leave or a day off, please talk to your client/manager first.
Then let us know the dates by e-mail ( We will then know not to wait for a timesheet if we don’t have all the timesheets for that month. This way, producing the payslip and paying your salary won’t be delayed.

If you cannot work because you are sick, please inform your superior and send an e-mail to by 9.30 am. Make sure that you are always contactable for you may receive an invitation from the occupational health and safety service. Use the above email address to notify us when you are fit to return to work.

Please also let us know when you have recovered. This is really important as we have to inform the occupational health and safety service (‘ARBO’), which in turn will inform the sick leave insurer. If you do not comply with the above, your salary will not be paid during your sickness. If you are sick for a longer period of time, the ARBO will be involved to speed up your recovery where possible. For the same reason it is important that you let us know where you are staying during your sickness and when you have recovered.

Personnel handbook 2022

There are different ways of working for organisations. Freelancers and self-employed workers without employees increasingly work through payroll companies because organisations increasingly use independent contractors. We make sure that the collaboration between companies, freelancers and self-employed workers proceeds smoothly. Together we will find a compliant construction that is beneficial to all parties and suits you.

Freelancers can enter our service under an employment contract. Being in Yellowstone’s employment has its advantages.

What we can do for you …

We invoice your client and pay you. This means you do not run any default risk. Payment is based on the hours worked, at the agreed hourly rate. We calculate the national insurance contributions, and ensure that all payments are made in the most tax-efficient way to optimise your net income. For instance, we can calculate certain costs as gross costs. And what if you have no assignments, or if you are sick? We keep you insured in terms of the Sickness Act, the Unemployment Act and the Work and Income (Capacity for Work) Act.

Also, you don’t have to keep accounts or register with the Chamber of Commerce. Those are the main advantages compared to working as a self-employed worker without employees.

Independent Contractors without Employees

Working at your own business (or as a self-employed worker without employees) may have tax advantages. But there are some things to keep in mind.

As you know, the Dutch Tax Authorities no longer issues Declarations of Independent Contractor Status. On 1 May 2017 the Assessment of Employment Relationships (Deregulation) Act took effect. This means that as a self-employed worker you should use a model agreement. Also see (Dutch only).


If you wish to work on a project as an independent contractor, we will ask the ultimate client to fill out a questionnaire to determine whether the project does not qualify as fictitious employment. We will then enter into a model agreement with your business, and we will become your client. You send us monthly invoices inclusive of VAT, which we will pay as soon as possible. The main difference with other constructions is that in this case we will not withhold any income tax and social insurance contributions.

How does it work …

Every month you have your manager or client fill out, approve and sign your time sheets. You then submit your time sheets plus your invoice to

We will then invoice the hours worked to the client. You will get paid after the client has paid the invoice.  Please contact one of our account managers if you have any questions.

What our customers think of Yellowstone

Oana 5/5 stars Thank you so much for your kind wishes!
You were the most extraordinary team I worked with!
All the best and thanks again for everything!
Arlene 5/5 stars I am grateful for your work ethic, support, communication style, thoroughness, patience, respective efficiencies, and advice.
Yellowstone to me, is 'The Standard' in terms of service, support, and professionalism.
Aditya 5/5 stars Thank you for taking care of all formalities regarding employment, hope to work with you in the future again.
Yvette 5/5 stars I'd like to thank you for all your great support over the past year, I am happy to work with you all.
João 5/5 stars It was a pleasure to collaborate with Yellowstone during all this time.
Himanshu 5/5 stars Thanks to you and your colleagues for all the help and support for the past 3 and half years.
The overall experience with Yellowstone was quite good for me :-)
Marieke & Rob 5/5 stars Yellowstone is the most pleasant company I/we have worked with so far! I will mention this to other people we work with.
Short lines, thinking along, friendly staff, knowledge of the business. Really a big 10!
Thank you very much.

Sumanth 5/5 stars I want to thank you Yellowstone for your support.
You helped me a lot throughout my journey.
I really appreciate it. You always responded quick for all my queries and helped me whenever you can. Cheers!
Sandeep Sharma 5/5 stars It’s been great working with Yellowstone and thank you for answering all my questions over the year with patience and clarity!
Tamal 5/5 stars I cannot thank you enough for your excellent help throughout my tenure with you.
Wish you all the best and hope we will work together in the future again.
Kamiel 5/5 stars I would like to take this opportunity to express my thanks for the clear and transparent communication at Yellowstone.
In the short time that we have had to deal with each other, I have always experienced the contact as warm and involved.
Many thanks for that. Keep up the good work.
Sahil 5/5 stars I would like to thank the entire team of Yellowstone for enabling my entire one year very smoothly.
Everybody was always reachable and was always keen to answer my emails and queries.