What Is a Tender Addendum in Construction?

A tender addendum is a formal change or supplement to the information issued to tenderers. It gives every affected bidder the same revised basis for pricing and responding before tenders close.

When should an addendum be issued?

Use one when a drawing, specification, scope, contract term, deadline or other tender requirement changes. A bidder’s question may uncover an inconsistency; if the answer changes the common tender basis, issue it through the agreed channel to all relevant tenderers. A private answer to one bidder can leave submissions incomparable.

What should it say?

Number and date the addendum. Identify superseded documents, attach the correct revisions, state exactly what changed and tell bidders whether the closing date or return schedules change. Maintain a register showing who received it and how acknowledgement will be recorded. Give enough time for a meaningful pricing response.

What happens at evaluation?

Confirm each tenderer priced the same set of addenda. If one bidder did not, clarify the position under the tender conditions before comparing prices. Preserve the questions, issued answers, document revisions and acknowledgements with the tender record.

Consider a revised services drawing issued two days before close. The question is not only whether the file reached every bidder. Check whether the affected trades can obtain revised prices and whether the client needs to extend the closing time under the tender conditions.

This discipline protects the client as well as the builder: a changed scope should be visible before award, rather than surfacing as a disputed variation later. Read about tender clarifications and our tender support.

Sources and further reading

• Buying for Victoria — fair and equal treatment of construction tenderers
• Victorian Department of Treasury and Finance — tender documentation