Providing top contract management for over 26 years.

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About Us

Welcome to Yellowstone International, your partner in contract management. We’re here to offer you support in all areas including all aspects of tax and employment law. Our subsidiary Yellowstone Contract Management B.V. will act as a formal employer.

With over 26 years of experience and a team of 22 professionals, we are a leader in the industry. Supported by our extensive (international) network of professionals, we make sure we always keep abreast of the latest in laws and regulations and compliance standards to maintain our position.

As the employer in legal terms, our subsidiary Yellowstone Contract Management B.V. arranges for payment and protects recipient companies against legal and tax liabilities. We also help obtain work permits, and solve immigration and relocation issues. From applying to visa to finding suitable accommodation, we’re here to help. On request we can help expats with practical matters like opening a bank account or registering with the municipality and healthcare institutions. As a relation of Yellowstone you can always call on us.

We like a customised and efficient approach, in which short lines of communication and a personal touch are key. No matter whether you are a recipient company, agency, employee or self-employed contractor. We turn your problem into the best possible solution.

Would you like to take advantage of all Yellowstone has to offer? Please get in touch.
We will be happy to tell you all about the boundless options.


Phone number

Our team


chief executive officer


Tax, Legal & Compliance


chief financial officer




Communication / Social Media / Events

Pront Aronson

Senior Account Operations Manager


Senior Account Manager

van Hout

Senior Account Manager


Junior Account Manager

Guus van
der Heijden

Junior Account Manager













de Jong


van der Steen




van Genugten


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.

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. 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 2024

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

Richard 5/5 stars I am writing to express my utmost admiration an appreciation for the exemplary services provided by Yellowstone. I wholeheartedly recommend Yellowstone to any professional seeking temporary work as a payment agent. Their unwavering dedication, professionalism and ability to deliver resullts make them an invaluable asset to any arganization.
Ranjani 5/5 stars I would like to express my heartfelt gratitude for all the help during my time as a consultant for Rhenus Logistics. If not for Yellowstone's timely assistance, the trajectory of the next few years of my life would've been greatly disturbed. Thank you so much for everything and good luck for all that is ahead!
Red Bee Media (100% subsidiary of Ericsson) 5/5 stars We are very satisfied with our cooperation with Yellowstone.
They provide the right support in the complicated employment law process for external employees.
A short clear questionnaire to determine the right category for our externals, and quick smooth setting up of the right contracts/agreements.
We took into consideration the risk of hiring freelancers ourselves and the amount of work involved in setting up the right contracts/agreements ourselves and coordinating them with the Tax Office, against the cost of hiring Yellowstone for this service.
It was quickly clear to us that Yellowstone could carry out and take over everything for us.
In short: we are very satisfied with the cooperation between Red Bee Media (100% subsidiary of Ericsson) and Yellowstone.
Martin 5/5 stars Can I take the opportunity to thank Yellowstone for the excellent service provided over the past year.
Any queries have been dealt with promptly, you have explained precisely what will happen and when - and it has.
All in all it’s been an extremely “hassle-free” service that appears to run seamlessly to me as a client. I appreciate that sometimes things may get very busy behind the scenes, but you have shielded me wonderfully well from that - which is the mark of an extremely competent service provider.
I hope that I will be using Yellowstone’s services again in the future, and I will certainly recommend you to others in my network.
José 5/5 stars It has been a real pleasure working with you. I have nothing but good things to say about you and the entire Yellowstone team.
Please pass on my thanks and affectionate greetings to all the team that I have worked with and have solved all my questions (which have not been few, I know).
Igor 5/5 stars It was a pleasure to work with you and Yellowstone company, I always had a top level of support for all questions.
Yellowstone Company had been chosen based on my friend's recommendation and I'm definitely going to recommend it to everyone.
Sebastian 5/5 stars Thank you very much for the opportunity to work with you for the past 2+ years.
I’ve enjoyed working with you and I’m very happy with the always excellent, professional support by 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.