We are determined to make the Netherlands proud of NS. To achieve this, we need to be able to rely on excellent suppliers. We deal with our suppliers based on the principles of objectivity, non-discrimination and proportionality. Clear agreements are indispensable to good collaboration. We base our agreements with suppliers on the following frameworks and guidelines.

General Terms and Conditions of Purchase

The General Terms and Conditions of Purchase contain the standard contractual conditions for agreements. The Public Procurement Act (Aanbestedingswet) does not allow conditional participation in tenders. Therefore, as a matter of principle, NS uses the same terms and conditions of purchase for all parties.


A number of companies within NS Groep qualify as a special sector company. Consequently, if the Public Procurement Act (Aanbestedingswet) requires, these companies put contracts for works, supplies and/or services out to European tender. This procedure is subject to threshold amounts. In cases where the contract value exceeds the threshold amount, NS has an obligation to launch a European tender procedure (subject to certain exceptions). In 2020, these thresholds amounted to 428,000 euros for supplies and services and 5,350,000 euros for works.

Read more about governance

In addition to the Public Procurement Act (Aanbestedingswet), NS also applies an internal governance policy for procurement. This means that NS must also observe internal procurement policy rules in addition to the Public Procurement Act. The main points of this governance approach are listed below.

  • Procurement takes place according to the law: we are transparent, objective, do not discriminate and work in accordance with the internal rules of conduct at NS.
  • Purchase commitments are authorised based on the ‘four eyes’ principle. This means that commitments only become binding after authorisation by Procurement and approval by the budget owner.

European Tenders

The European tender process is designed to give all companies the opportunity of competing for a contract within the public domain.

Read more about European Tenders

There are four European Tender variants:

  • Restricted procedure;
  • Negotiated procedure with a call for expression of interest;
  • Public tender procedure;
  • Qualification system.

The restricted procedure includes a selection split early in the tender process. Initially, a number of parties are selected in the RFI phase. The selected parties are then invited to submit a quotation in the RFP phase. This is referred to as a restricted procedure because only the suppliers selected in the RFI phase are sent the complete specifications and given the opportunity of submitting a quotation. This selection split and the associated minimum periods lengthen the total completion period for the tender but reduce the administrative load on the tender candidates and NS compared to the public tender procedure.

The only difference between the negotiated procedure with expression of interest and the restricted procedure is that the former includes a negotiation meeting with one or more parties during the RFP phase.

In the public tender procedure, selection and contract award are assessed at the same time. This procedure is referred to as a public procedure because all the interested parties are permitted to view the complete set of specifications.

The qualification system procedure is a continuous process where suppliers have to demonstrate suitability for collaborating with NS within a certain field of work in order to qualify. When a contract subsequently arises within that field of work, NS is only required to approach qualified suppliers and request them to submit a quotation.


NS publishes notifications of all of its European tenders on Tenderned.


NS attaches importance to ensuring that the procedure offers equal opportunities for all parties. This is why NS uses the Ariba platform. You can view the tender information and upload the documents you are required to submit via Ariba. Ariba is also used for all communication during the tender procedure.

Ariba is an encrypted platform and NS is only permitted to view the documents you have submitted for a European tender after the submission period has expired. This guarantees a level playing field for all parties.

Market-driven innovation

NS sees suppliers as experts that make an important contribution to improving our strategic position further. This is unavoidable, as the market changes continuously and new developments are launched in rapid succession. As a result, and based on your professional perspective, you may see opportunities for NS to set up its operations better, more cost-effectively, more efficiently or completely differently.

If you believe that you may be a potential supplier for NS (see our criteria for suppliers), we would welcome further discussion with you.

Please contact NS Procurement Support.