Addendum / Corrigendum

An addendum (also called a corrigendum, amendment, or clarification bulletin) is a formal notice issued by the contracting authority during the active tender period to update, correct, or supplement the original tender documents. Corrigendum is the EU/formal legal term for an amendment that corrects an error; addendum typically adds new information or changes requirements.

Tender documents frequently require amendment for several reasons: factual errors discovered post-publication, changes in scope or specification, responses to clarification questions that have broader relevance to all bidders, changes to submission deadline or format, and updates to contract terms. Each addendum must be issued to all tenderers simultaneously to maintain equal treatment, and on public portals it must be published openly.

For vendors, monitoring addenda is a non-negotiable process discipline. Missing an addendum can mean submitting against superseded specifications — a significant risk of disqualification or delivering a non-compliant solution. E-procurement platforms typically send automated notifications when addenda are published; vendors should also check the portal manually close to submission deadline. If an addendum materially changes the specification or timeline, vendors may request a submission deadline extension — a right in some jurisdictions but at the authority's discretion in others.