The Dutch Proportionality Guide: what it means for you as a bidder

What is the Proportionality Guide?

The Aanbestedingswet 2012 (the Dutch Public Procurement Act) says that a public buyer may only set requirements, conditions and criteria that are in reasonable proportion to the contract. What that means in practice is set out in the Gids Proportionaliteit. It covers the whole procurement process: the choice of procedure, the size of the contract, the selection criteria, time limits and contract terms. It consists of explanatory text and numbered rules.

The current version is the third revision, in force since January 2022. It is published by PIANOo, and an English translation is available. The guide applies to European and national tenders and to multiple private tender procedures, where a buyer invites a few companies directly. How that works below the EU thresholds is explained in public contracts below the threshold.

Comply or explain

The guide is not optional advice. The Public Procurement Act provides for a designated guideline on the requirements a buyer sets: for European tenders in article 1.10, for national tenders in article 1.13 and for multiple private tenders in article 1.16. Article 10 of the Aanbestedingsbesluit (the Public Procurement Decree) designates the Proportionality Guide as that guideline.

One rule comes with it. The buyer applies the rules, or explains in the tender documents why it departs from them. This is comply or explain. Departing is allowed, but not without an explanation. If a requirement goes further than the guide and no reason is given, you have a strong point. If a reason is given, you can still question it: the departure must also be justified.

Departing from the guide is allowed. Departing without an explanation is not.

The rules that matter in practice

The guide is long. For a bidder, these are the parts that most often make the difference. Some are in the Act itself, some in the guide. The numbers refer to the third revision. When in doubt, read the text of the guide itself.

• TurnoverAt most three times the contractA turnover requirement is the exception. In a European tender, the buyer must give significant reasons for it, and it may not exceed three times (300%) the estimated value of the contract (article 2.90 of the Act).
• ReferencesOne per core competence, at most 60%The buyer names core competences and asks for no more than one reference per core competence. A reference need not be larger than 60% of the estimated value (rule 3.5 G). More in references.
• RequirementsOnly what fits the riskSelection criteria must be connected with the real risks of the contract or with the competences required (rule 3.5 B).
• BundlingNot unnecessarily largeContracts are not bundled unnecessarily. A contract is divided into lots, unless the buyer explains in the documents why that is not appropriate (article 1.5 of the Act).
• Framework agreementNo free standbyIn a framework agreement, the buyer may not require you to keep staff, equipment or materials available without a turnover guarantee or a fee (rule 3.3 A).
• ContractLimited liabilityUnlimited liability is not allowed. To set the cap, the buyer looks at the risks it actually runs and at what is usual in the sector (rule 3.9 D). Where jointly drafted industry terms exist, it applies them in full (rule 3.9 C).

And one rule many bidders overlook: during the procedure, the buyer gives you the chance to suggest changes to the draft contract (rule 3.9 B). You do not have to take the contract as it stands.

From requirement to action

This is how you hold a requirement from the tender documents against the Act and the guide. The requirements in the first column are fictional examples.

Start with a question

The first place to raise a requirement is the clarification round, called the nota van inlichtingen in Dutch tenders. Name the requirement with its section and page, cite the rule or the article, and propose an alternative that still serves the purpose of the requirement. A buyer who sees that a requirement falls outside the guide without a stated reason has good grounds to change it. More on building such a question in selection criteria and knock-outs.

Do not wait. The guide expects you to raise an objection as soon as reasonably possible after publication. If you only challenge a requirement after submitting your bid, you risk being too late.

Challenge a disproportionate requirement before you bid, not after.

If a question does not help: the complaints route

1. 1Complaint to the buyerSubmit your complaint in writing to the buyer itself, through its complaints desk if the tender documents name one. PIANOo’s guidance on complaint handling expects you to ask questions in the clarification round first, and only then file a formal complaint. Support it with the rule and the page.
2. 2Public Procurement Expert CommitteeIf you are not satisfied with how the buyer handled your complaint, you can turn to the Commissie van Aanbestedingsexperts. This is free of charge. The condition is that you first complained in writing to the buyer and gave it a reasonable time to respond. The committee’s advice is not binding.
3. 3The courtFor a binding ruling you go to the civil court, in urgent cases through summary proceedings (kort geding). If a court case about the tender is already pending, the committee will not take up the complaint.

Note: since 20 November 2025, the committee only handles complaints about the design of a tender. These are complaints about what the buyer fixed in advance: the requirements, conditions and criteria. It no longer takes up complaints about selection or award decisions. For a disproportionate requirement that makes no difference, because you raise it before you bid anyway. What you can do after an award decision is covered in after the award decision.

There is also a bill to strengthen legal protection in Dutch public procurement, including a mandatory complaints procedure at contracting authorities. It was sent to the Dutch House of Representatives in December 2025. Check PIANOo for its current status.