An agreement between the public buyer and its contractor does not by itself make a contract change lawful. Section 132 GWB determines when a modification can be made without a new procurement in its field of application.
Identify the change and its effect
Compare the proposed arrangement with the contract originally competed. A modification can be material if it would have attracted other participants, permitted a different tender, shifted the economic balance or substantially extended the scope. A change of contractor also requires particular attention. The analysis concerns the overall substance, not only the name given to the amendment.
Check the legal basis
Clear, precise and unequivocal review clauses can provide a basis for specified changes. Other statutory grounds address, among other matters, certain additional requirements and unforeseen circumstances. Each has its own conditions, limits and possible publication requirements. Percentage limits should never be treated as a general permission independent of the relevant provision.
Record the decision before ordering
Document the original scope, proposed change, reasons, value, previous modifications and the selected statutory basis. The contractual entitlement to additional payment is a separate question from whether a new procurement is required. Below the EU thresholds, identify the applicable national provisions instead of assuming that every GWB rule applies directly.
Keep control throughout performance
Project teams should escalate changes before they become commitments. Maintain a change register and monitor options, volumes and cumulative effects. A small technical adjustment may have significant economic consequences, while an expressly competed option may already be covered by the original arrangement.
Four practical examples
The following scenarios are illustrative, not reports of actual client matters. The outcome depends on the documents and circumstances of the individual procurement.
Example 1: Renewal option
A service agreement contains a defined extension option. Check whether its wording and original competition cover the intended extension. A vague right to order anything later is not an equivalent safeguard.
Example 2: Additional works
Unexpected work is requested on a construction site. Assess the precise statutory ground, value limits and publication duties before instructing the contractor. Being on site is not enough to justify a direct extension.
Example 3: Price adjustment
The supplier seeks a higher price without changing the service. Review the contractual clause and the effect on the economic balance. An unchanged technical output does not make every price increase immaterial.
Example 4: New group company
A related company is to replace the contractor. Examine succession, capability and the legal conditions for replacement. Common ownership alone does not authorise any transfer of the public contract.
Related topics
Framework agreements and call-off contracts · Public works procurement under the VOB/A · Unlawful direct awards and ineffectiveness
Discuss your procurement
For a review, please identify the authority, contract or lot, current procedural stage and any deadline. We can then clarify the scope of the requested work. Contact our team. An enquiry does not itself create a retainer or preserve a legal deadline.
Legal sources
Official legislation and materials, some in German: § 132 GWB – Auftragsänderungen · § 106 GWB – Schwellenwerte · § 8 VgV – Dokumentation
Updated 13 November 2026. Illustrative guidance on German and EU procurement law.