Bidders' Duty to Cooperate in Procurement Law 2026

Bidders' duty to cooperate: bidders' obligations to actively participate in the tender procedure, e.g. in clarification interviews and provision of evidence.

Definition: The bidders' duty to cooperate describes the procurement-law obligation of bidders and applicants to actively participate, within a tender procedure, in clarifying the contents of bids, submitting evidence, and answering follow-up questions from the contracting authority, in order to enable the examination and evaluation of their bid.

Last updated: January 2026 · Legal basis: BVergG 2018, VgV, VOB/A, GWB

Basis of the duty to cooperate

The duty to cooperate is not an independent statutory entitlement; it arises from the principle of good faith and from the specific provisions on bid clarification in procurement law. It does not require bidders to provide information actively without being asked, but it does require them to respond to requests from the contracting authority in good time and in full. Failure to comply with this duty can result in the bid being excluded as non-evaluable.

In procurement law, a clear distinction must be drawn between the subsequent submission of missing documents (which is permissible under certain conditions) and the substantive remedying of defects (which is in principle not permitted). The duty to cooperate primarily concerns the subsequent submission of evidence and the explanation of the bid content.

Areas of application

In practice, the duty to cooperate arises mainly in three constellations.

Clarification interviews

If the contracting authority identifies ambiguities during the examination of a bid, they can request the bidder to clarify. The bidder is required to respond fully and truthfully. An evasive or incomplete answer can result in the bid being excluded.

Submission of suitability evidence

If the contracting authority requests missing suitability evidence, the bidder must provide it within the set deadline. In Austria, § 132 BVergG 2018 provides that the contracting authority may, under certain conditions, request missing or defective documents. The bidder must comply with this request.

Clarification of abnormally low bids

If a bid appears abnormally low in relation to the performance, the contracting authority is required to ask the bidder for clarification (§ 125 BVergG 2018; Art. 69 Directive 2014/24/EU). The bidder must explain the costing in a comprehensible way. If they fail to comply with this duty or the explanation is not convincing, the bid may be excluded.

Limits of the duty to cooperate

The duty to cooperate reaches its limit where it would tip over into an inadmissible improvement of the bid. The bidder may not, in the course of cooperation, make substantive changes to their bid or adjust prices. The principle of equal treatment prohibits granting any bidder, through cooperation, advantages over other bidders who had no opportunity to improve their bid.

Related terms

FAQ

Can a bidder be forced to submit missing documents? The bidder cannot be legally forced. They do, however, bear the risk that their bid will be excluded if they do not comply with the request for subsequent submission.

Does the duty to cooperate also apply in the negotiated procedure? Yes; in the negotiated procedure too, bidders are required to respond to the contracting authority's questions and requirements in good time.

May a bidder subsequently increase an abnormally low bid? No. In the course of clarification, the bidder can only explain the costing; they cannot subsequently change the price.

Last updated: January 2026 All information without guarantee. For legally binding advice, please contact a law firm specialising in procurement law.