Inquisitorial Principle in Public Procurement Law 2026

Definition: The inquisitorial principle (Amtsermittlungsgrundsatz, also: investigation principle) obliges the public procurement chamber to investigate of its own motion the facts relevant to the decision in review proceedings, without being bound by the applications and submissions of the parties.

Last updated: January 2026 · Legal status: GWB § 163, VwVfG

---

What is the inquisitorial principle in public procurement law?

The inquisitorial principle is a fundamental procedural principle in procurement review proceedings before the public procurement chambers and obliges them to clarify the facts comprehensively, independently of the submissions of the parties. It is anchored in § 163(1) GWB and substantially distinguishes the procurement review procedure from the civil-procedure adversarial principle that applies before the ordinary courts. Pursuant to § 163(1) GWB, the procurement chamber investigates the facts of its own motion and uses all means of investigation available to it.

Content and scope

The inquisitorial principle empowers and obliges the procurement chamber to investigate all facts relevant to the decision, even where the parties have not raised them.

In concrete terms this means:

• The procurement chamber is not limited to the facts submitted by the parties
• It may conduct its own investigations and take evidence
• It may request documents from the contracting authority (in particular the procurement file)
• It may call expert witnesses
• It may obtain information from third parties

The inquisitorial principle is not unlimited, however: the procurement chamber is bound by the subject matter of the review proceedings and may not go beyond the application (ne ultra petita). The time limits of § 167 GWB (five-week decision deadline) also limit the scope of possible investigations.

Distinction from the adversarial principle

By contrast with the inquisitorial principle, the adversarial principle applies in civil proceedings and in the OLG appeal procedure: here the parties bring forward the facts and the court decides only on the basis of the facts presented. The Higher Regional Court (OLG) as the immediate appellate instance (§§ 171 et seq. GWB) is therefore not obliged to investigate of its own motion to the same extent as the procurement chamber.

Practical significance

For applicants in review proceedings, the inquisitorial principle is a substantial relief, since they do not need to plead and prove all procurement-law relevant facts themselves.

The procurement chamber can in particular:

• Obtain the complete procurement file from the contracting authority
• Review redactions in the procurement file
• Independently clarify questions on the tender evaluation

Nevertheless, applicants should plead all known and grievance-relevant facts comprehensively and substantively, as this significantly influences the procurement chamber's decision.

FAQ

Does the inquisitorial principle also apply before the OLG? No. As a civil court, the OLG is essentially bound by the adversarial principle. It may, however, conduct its own investigations to a limited extent.

Can the procurement chamber act without an application? The procurement chamber only initiates review proceedings on application. Within initiated proceedings, however, it then investigates the facts of its own motion.

What happens if the contracting authority fails to produce the procurement file? The procurement chamber may order production of the file. If the contracting authority refuses to produce, this may be held against the contracting authority.

---

Last updated: January 2026 All information provided without warranty. For legally binding advice, consult a law firm specialising in public procurement law.