Contract Modifications Public Procurement Denmark, Udbudsloven (2026)

Quick answer: can public contracts be modified in Denmark under Udbudsloven?

Contract modifications public procurement Denmark rules allow a public contract to be changed during performance, but only within defined limits set by the Danish Public Procurement Act (Udbudsloven), which implements EU Directive 2014/24/EU. The modification rules are set out principally in sections 178 to 184 of Udbudsloven. In short: non-substantial modifications are permitted without a new tender, while substantial modifications require a fresh procurement procedure. A modification is “substantial” where it materially alters the economic or contractual balance of the original award, for example, by introducing conditions that would have attracted different bidders, changing the contract’s scope significantly, or shifting the economics in the contractor’s favour.

The distinction matters because an unlawful change exposes the authority to complaints before Klagenævnet for Udbud (the Danish Complaints Board for Public Procurement), potential declarations of ineffectiveness, and damages.

The EU procurement thresholds are revised every two years by the European Commission, with the current values applying from 1 January 2024 and the next revision expected from 1 January 2026. Because thresholds determine when the full regime applies, they also affect how modifications and extensions are assessed. Authorities should always check the thresholds currently in force. This guide sets out the statutory basis, the CJEU “substantial modification” test as applied by Klagenævnet, and practical documentation steps so that contract modifications in Danish public procurement can be handled defensibly.

When is a modification permitted under Udbudsloven?

Udbudsloven codifies the circumstances in which an existing public contract may be amended without re-running a procurement procedure. The governing principle is that the contract as performed must remain, in substance, the contract that was competitively awarded. Where a proposed change stays within the permitted categories, contract modifications in public procurement in Denmark can proceed lawfully; where it crosses into “substantial” territory, a new tender is required.

Statutory anchors and EU law

The Danish rules on modification derive directly from Directive 2014/24/EU, which harmonised the treatment of in-term contract changes across the EU. Udbudsloven transposes those provisions, and the consolidated statutory text is published on Retsinformation, the official Danish legal information portal. The Directive establishes both the general prohibition on substantial modification and a set of “safe harbour” grounds under which changes are permitted. Because the Danish provisions mirror the Directive, CJEU jurisprudence interpreting the EU test is directly relevant to how Danish authorities and Klagenævnet apply Udbudsloven.

Typical permissible non-substantial changes

Several categories of change are generally permitted without a new tender, provided their conditions are met:

• Clear, precise review clauses. Changes foreseen in the original tender documents through unambiguous review, option or price-revision clauses that state the scope, nature and conditions of the modification.
• Low-value modifications. Changes below the relevant financial thresholds that do not alter the overall nature of the contract.
• Additional works, services or supplies that have become necessary and where a change of contractor is impossible for technical or economic reasons and would cause significant inconvenience or duplication of cost.
• Administrative and technical adjustments, updating contact details, correcting clerical errors, or reflecting immaterial technical refinements that do not affect price, scope or competitive balance.
• Modifications arising from unforeseeable circumstances that a diligent authority could not have anticipated, where the overall nature of the contract is unchanged.

Each ground has its own conditions and limits. A change that is administrative in appearance may still be substantial if it affects the economic balance, so authorities must assess the practical effect rather than the label.

Required documentation and audit trail

Even where a modification is plainly non-substantial, contracting authorities should maintain a contemporaneous audit trail. Danish regulatory guidance from Konkurrence- og Forbrugerstyrelsen (the Danish Competition and Consumer Authority) emphasises procedural discipline and supervision of procurement practice. A robust file supports the authority if the change is later challenged before Klagenævnet. Recommended records include: a written note identifying the legal basis for the modification under Udbudsloven; a description of what is changing and why; a value analysis showing the change stays within permitted limits; confirmation that no review clause was exceeded; and an internal sign-off by an authorised officer. Where a review clause is relied on, the file should cross-reference the exact clause in the original tender documents.

Where “unforeseeable circumstances” are invoked, the file must explain why a diligent authority could not have anticipated the event. The discipline of documenting the reasoning at the time, rather than reconstructing it after a complaint, is the single most effective protection against a finding that contract modifications in public procurement in Denmark were made unlawfully.

Substantial modification, legal test, consequences and Danish practice

The concept of “substantial modification” is the pivot point of the entire regime. Understanding where the line falls, and what happens if an authority crosses it, is essential for anyone managing contract modifications public procurement Denmark issues in practice.

The CJEU test explained

The “substantial modification” test originates in CJEU case law, notably the pressetext judgment, and is now codified in Directive 2014/24/EU and transposed into Udbudsloven. A modification is treated as substantial, and therefore requires a new procurement procedure, where it renders the contract materially different in character from the one originally concluded. The Court has identified indicative triggers. A change is substantial where it:

• introduces conditions that, had they been part of the original procedure, would have allowed for the admission of different candidates or the acceptance of a different tender, or would have attracted additional participants;
• changes the economic balance of the contract in favour of the contractor in a manner not provided for in the original terms;
• extends the scope of the contract considerably to encompass works, services or supplies not initially covered; or
• replaces the contractor other than in the limited circumstances the Directive permits.

The underlying rationale, consistently expressed by the CJEU, is that allowing substantial in-term changes would circumvent the transparency and equal-treatment obligations that govern the initial award. The relevant judgments are available through the CURIA case-law search portal.

How Klagenævnet applies the test

Klagenævnet for Udbud applies the CJEU test directly when reviewing Danish contract modifications. In its decisions, the Board examines whether the modified contract remains within the contours of the original award and whether the change could have influenced the field of bidders or the outcome. Typical scenarios that have drawn scrutiny include the addition of significant new deliverables, extensions of duration well beyond what the original tender contemplated, and changes to core pricing structures. The Board looks past the parties’ characterisation to the substance: it assesses whether the modification alters the economic balance or the competitive conditions that governed the award.

Where authorities have relied on review clauses, the Board tests whether those clauses were sufficiently clear and precise to have put bidders on notice. Where they have relied on “unforeseeable circumstances”, it tests whether a diligent authority genuinely could not have anticipated the event. Decisions of Klagenævnet are published on the Board’s website and provide the most reliable indication of how the test operates in Danish practice.

Consequences of a wrong modification

Red flag: treating a substantial change as if it were a minor one carries real legal exposure. A modification that should have triggered a fresh tender is, in effect, an unlawful direct award. Depending on the facts, consequences can include a declaration that the modified contract is ineffective, orders to bring the procurement into compliance, financial penalties, and liability in damages to bidders who were denied the opportunity to compete. The reputational and audit consequences for the authority can be significant. These risks make the substantial/non-substantial assessment the most important single judgement in managing contract modifications in Danish public procurement.

Extending contracts and exercising renewal options

Extensions are among the most common in-term changes, and they are also among the most frequently mishandled. An extension of duration is a modification like any other and must be tested against the substantial-modification rules. The value of an extended contract is relevant to whether the full regime applies and to how any residual competition should be conducted.

Renewal options, drafting and limitations

The cleanest way to extend a public contract in Denmark is to have provided for the extension in the original tender through a clear renewal option. To be relied upon lawfully, an option must be set out with sufficient precision in the original documents: it should state the maximum duration of any extension, the conditions under which the option may be exercised, and, critically, how price and scope will be treated during the extended period. An option that is vague, open-ended or silent on price cannot safely be used to extend the term, because bidders could not have priced or evaluated it at the time of award.

Well-drafted options allow authorities to extend without a new procedure precisely because the extension was part of the competed-for bargain. The estimated total value used in the original tender should have included the maximum foreseeable option value, so that the threshold assessment was correct from the outset.

Extensions beyond original scope or term, risk factors

Key test: can the extension be traced back to a clear clause or a permitted safe-harbour ground? If not, extending the term or scope is likely to be substantial. Extending a contract simply because re-tendering is inconvenient, or because the incumbent is performing well, is not a lawful basis. Extensions that materially increase the contract’s value, prolong duration well beyond what bidders anticipated, or add new categories of work are the highest-risk category and frequently attract challenge.

Practical approval checklist for extensions

Before exercising any extension, authorities should confirm:

1. Is the extension covered by a clear, precise option or review clause in the original tender documents?
2. Was the option’s value included in the original estimated contract value?
3. Does the extension leave the overall nature of the contract unchanged?
4. Has the extended value been checked against the thresholds currently in force?
5. Is there a written internal approval recording the legal basis for the extension?

Changing the supplier during performance, substitution, succession and change of contractor under Udbudsloven

Replacing the contractor mid-contract is one of the most sensitive modifications, because “change of contractor” is one of the express triggers for substantial modification. As a starting point, a new contractor cannot simply take over a public contract without a new procurement procedure. The Directive and Udbudsloven, however, recognise a limited set of circumstances in which a change of contractor is permitted.

Permitted supplier replacement scenarios

A change of contractor may be lawful without a new tender in defined situations:

• An unambiguous review clause. Where the original tender documents contained a clear and precise clause providing for a change of contractor and the conditions for triggering it.
• Universal or partial succession. Where the original contractor is succeeded by another economic operator following corporate restructuring, including takeover, merger, acquisition or insolvency, provided the successor meets the original qualitative selection criteria and the succession does not entail other substantial modifications intended to circumvent the rules.
• Assumption by the authority. Where the contracting authority itself assumes the main contractor’s obligations towards its subcontractors, in the limited circumstances the rules allow.

Outside these grounds, substituting the supplier is treated as a substantial modification requiring re-tendering.

Supplier insolvency, assignment and change of control

Supplier insolvency is a recurring practical trigger. Where an incumbent becomes insolvent, the authority cannot simply hand the contract to a new provider of its choice; it must fit the transfer within a permitted succession ground or run a new procedure. Corporate reorganisations, mergers, demergers and changes of control, must be assessed carefully: the successor must satisfy the original selection criteria, and the reorganisation must not be a device to introduce other changes that would themselves be substantial. Assignment of a contract to an unrelated third party outside a genuine succession will generally be unlawful. Authorities should verify the successor’s financial standing, technical capacity and any exclusion grounds before accepting a change of contractor, and should document that verification.

Drafting supplier-change clauses

Where a change of contractor is foreseeable, for example, in long-term contracts or where group restructuring is likely, a well-drafted clause can preserve continuity. The clause should specify the circumstances in which substitution is permitted, require the incoming contractor to demonstrate compliance with the original selection criteria, require evidence of financial and technical capacity, and reserve the authority’s right to verify and, where justified, refuse a proposed successor. Robust drafting reduces the risk that a later change of contractor under Udbudsloven is characterised as an unlawful substantial modification.

Price changes and variation clauses, permitted price increases and formulas

Price is often where in-term disputes arise, because contractors seek increases and authorities must judge whether an increase is lawful. A price change that alters the economic balance in the contractor’s favour, and is not provided for in the original terms, is a classic substantial modification.

Typical lawful price revision mechanisms

Lawful price changes almost always trace back to a mechanism agreed at the outset. The most reliable is a clear indexation or price-revision clause in the original tender documents. To be relied upon, such a clause should state the trigger for revision, the reference index or formula, the frequency of adjustment, and any cap. Because the mechanism was competed for, applying it during performance does not distort the original award. Price adjustments made strictly in accordance with a precise formula are, in principle, permitted price variations rather than new modifications. Authorities should retain the calculation and the underlying index data each time the mechanism is applied.

When a price change may be substantial

Red flag: an ad-hoc price increase negotiated during performance, with no basis in the original contract, is likely to be substantial, particularly if it materially improves the contractor’s position or if a lower price was decisive in the original award. The question is whether the change alters the economic balance in a way not provided for. Even a change framed as a “cost pass-through” can be substantial if it exceeds what any review clause permits. Where cost pressures arise that the original clauses do not address, the safer route is usually a fresh procedure rather than an unsupported price hike, unless a specific safe-harbour ground genuinely applies.

Exceptional grounds for modification, extreme urgency, unforeseen circumstances and force majeure

A narrow set of exceptional grounds can justify changes that would otherwise require competition. These grounds are construed strictly and the burden is on the authority to justify their use.

Extreme urgency criteria

The extreme-urgency ground is exceptional. It generally requires that the urgency is genuine, that it results from events unforeseeable by the authority, and that the urgency was not attributable to the authority’s own delay. Foreseeable pressures, poor planning or self-induced time constraints do not qualify. Because this ground overlaps with the rules on direct awards, authorities considering it should treat it as a last resort and confine it to what is strictly necessary to address the immediate situation.

Documentation and retrospective justification

Where an exceptional ground is relied on, contemporaneous documentation is decisive. The file should record the triggering event, why it was unforeseeable, why the modification is limited to what the circumstances require, and why no compliant alternative was available in the time frame. Retrospective justification assembled only after a challenge is far weaker than a record made at the time. Authorities should also confirm whether any transparency or notice obligations apply and comply with them.

Compliance checklist and decision tree for contracting authorities

The following ten-step checklist helps assess whether a proposed change can proceed as a permitted modification or requires a new procedure:

1. Identify exactly what is changing, scope, price, duration, contractor or terms.
2. Check whether a clear, precise review, option or price-revision clause in the original tender documents already covers the change.
3. If no clause applies, test the change against the CJEU “substantial modification” triggers.
4. Assess whether the change could have attracted different bidders or a different outcome.
5. Assess whether the change alters the economic balance in the contractor’s favour.
6. Check the value of the change against the relevant thresholds and permitted limits currently in force.
7. For a change of contractor, confirm a permitted succession or clause-based ground applies and verify the successor’s qualifications.
8. If an exceptional ground (unforeseeability, extreme urgency) is invoked, document why it genuinely applies.
9. Obtain and record internal approval identifying the legal basis under Udbudsloven.
10. Retain the full audit trail and comply with any applicable notice or transparency obligations.

If steps 2 to 8 confirm the change falls within a permitted category, it can generally proceed. If not, the default position is that a new procurement procedure is required.

Comparison table, non-substantial vs substantial modifications

Practical drafting tips and sample clause language

Good drafting at the tender stage prevents most in-term disputes. Because permitted modifications largely depend on what was foreseen in the original documents, the tender is where compliance is won or lost. The following model wording illustrates the drafting approach; each clause should be tailored to the specific contract and checked against the current Udbudsloven text.

Variation clause (illustrative): “The Authority may direct changes to the scope of the Services within the limits set out in this clause. Any such variation shall be documented in a written change order stating the revised scope, the corresponding price adjustment calculated under [Schedule X], and the effective date. Variations shall not alter the overall nature of the Contract.”

Price revision clause (illustrative): “Prices shall be adjusted annually on [date] by reference to [named index] published by [source], applying the formula set out in [Schedule Y]. Adjustments shall not exceed [cap]. No other price change shall apply save as expressly permitted by this Contract.”

Supplier substitution clause (illustrative): “Where the Contractor is succeeded by another economic operator through corporate restructuring, the successor shall assume the Contract only where it satisfies the selection criteria applied in the original procurement and provides evidence of financial and technical capacity. The Authority reserves the right to verify such compliance and to refuse a successor that does not meet the criteria.”

Each clause must be clear, precise and value-bounded to satisfy the review-clause safe harbour. Vague or open-ended wording will not support a later modification. Retain a record whenever a clause is exercised, and confirm that exercising it keeps the contract within the estimated value used for the original threshold assessment.

Conclusion

Handling contract modifications public procurement Denmark issues well comes down to one disciplined judgement repeated across every in-term change: is the modification within a permitted category, or is it substantial? Permitted changes, clear review clauses, agreed price formulas, genuine renewal options, necessary additions and lawful successions, can proceed, but only where the conditions are met and documented. Substantial changes require a new procedure, and getting this wrong invites complaints to Klagenævnet, ineffectiveness and damages. Use the ten-step checklist, draft precise variation, price and substitution clauses at tender stage, and keep a contemporaneous audit trail. Where a proposed change sits close to the line, obtain specialist advice before committing.

Sources

1. Business in Denmark, Public Procurement Act (Virk)
2. Retsinformation, official Danish legal information
3. Klagenævnet for Udbud (Danish Complaints Board for Public Procurement)
4. Konkurrence- og Forbrugerstyrelsen, Udbud
5. EUR-Lex, Directive 2014/24/EU on public procurement
6. Court of Justice of the European Union (CURIA), case law search
7. OECD, Public Procurement policy and guidance