A tender that is strong in substance but formally flawed can be excluded before the substantive assessment even begins. Irregularities — from missing signatures to deviating price statements — are one of the most common reasons tenderers miss out on a contract. The distinction between a substantial and a non-substantial irregularity determines whether the error is fatal or can be corrected.
What is an irregularity?
An irregularity is any deviation in the tender from the requirements of the specifications, the notice or the law. The Royal Decree on Placement of 18 April 2017 (Articles 76 and 82) distinguishes between two categories.
Substantial irregularities
A substantial irregularity is a defect that:
- affects the equal treatment of tenderers,
- modifies the subject matter of the contract,
- makes assessment of the tender impossible, or
- distorts competition.
Substantial irregularities mandatorily lead to the nullity of the tender. The authority has no discretion here — a tender with a substantial irregularity must be excluded.
Examples:
- Failure to respect the submission deadline. Late is late — the system automatically blocks the submission.
- A reservation regarding essential specification conditions. If you do not accept a contractual condition, you modify the subject matter of the contract.
- The absence of a price for an item designated as substantial in the specifications. An incomplete price proposal makes comparison impossible.
- Submission in the wrong language. If the specifications prescribe Dutch, a tender in French is null.
- A signature defect where the signatory is not authorised and that defect is not rectified in time.
Non-substantial irregularities
A non-substantial irregularity is a defect that does not distort competition and does not make assessment impossible. The authority may in this case retain the tender, possibly with a request for clarification or completion.
Examples:
- A missing annex that is not essential to the assessment.
- An arithmetic error in the pricing (unit price × quantity) — the authority adjusts the total price based on the unit price.
- A formal error in the signature that can be corrected.
- An incomplete declaration that can be supplemented without modifying the substance of the tender.
The power to request clarification
Article 76, §2 of the Royal Decree on Placement allows the authority to ask tenderers to clarify or supplement their tender. This is however not an obligation — the authority has discretionary power.
Limits of clarification
The right to request clarification has clear limits:
- The clarification may not materially modify the tender. You may supplement a missing document, but not submit a new price.
- The clarification may not result in what is effectively a new tender.
- The authority must treat all tenderers equally. If it gives one tenderer the opportunity to supplement a document, it must do so for others in comparable situations.
Common errors and how to avoid them
Price-related irregularities
Unfilled items in the bill of quantities. For works contracts, the bill of quantities is binding. An empty item is usually deemed to be included in other items — but if the specifications provide otherwise, it can lead to exclusion.
Material arithmetic errors. Where the unit price and total price differ, the unit price generally prevails. Where the amount in figures and in words differs, the amount in words prevails. But these rules only apply if the specifications do not provide otherwise.
Abnormally low price. If the offered price appears abnormally low, the authority must ask the tenderer for a justification before it can exclude the tender. The tenderer is given the opportunity to demonstrate that its price is realistic.
Form-related irregularities
Signature. The tender must be signed by a person authorised to bind the tenderer. If the signatory is not listed in the commercial register as a director, a power of attorney must be enclosed.
Electronic submission. On e-Tendering, the correct file format must be used. A corrupted file or a file that cannot be opened is an irregularity.
Language. The tender must be drafted in the language of the specifications. In bilingual procedures, specific rules apply about which documents must be in which language.
Substantive irregularities
Deviation from technical specifications. If the specifications prescribe a specific product or standard and the tenderer offers an alternative without the specifications allowing variants, this is a substantial irregularity.
Reservations. Any clause in the tender that deviates from the contract conditions in the specifications is a reservation. Minor nuances are sometimes tolerated — fundamental reservations never.
Missing references or certificates. If the specifications require specific references or certificates as a selection criterion and these are missing, the tender can be excluded. But if the evidence can also be supplemented after submission (such as the ESPD), the defect may be remediable.
The compliance checklist
Experienced bid managers work with a compliance matrix that checks the specification requirements against the tender point by point. A minimum checklist includes:
- Are all requested documents enclosed (ESPD, reference list, technical data sheet, pricing schedule)?
- Is the tender signed by an authorised person with enclosed power of attorney if needed?
- Are all items in the pricing schedule filled in?
- Are the arithmetic operations correct (unit price × quantity = total)?
- Is the tender drafted in the correct language?
- Are all requested certificates and attestations current?
- Are any variants submitted only if the specifications permit this?
- Was the tender submitted before the deadline on e-Tendering?