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Addendum (bid addenda)

An addendum is an official change to a bid or RFP issued before the deadline, such as new answers, changed quantities or a new due date. Bidders must usually acknowledge every addendum or their bid can be rejected.

Counties issue addenda to answer bidders' questions, fix errors, change specifications or move the deadline. Each addendum becomes part of the bid documents.

The rule that catches bidders out

Most bid forms include a line to acknowledge each addendum by number (for example, "Addenda received: 1, 2, 3"). If you miss one, the county may treat your bid as non-responsive, even if the addendum was minor.

Good habits

  • Register with the county or its bid platform so you are notified.
  • Check the posting again the day before you submit.
  • Price the bid from the latest documents, not the originals.
  • Acknowledge every addendum in the place the bid form asks.

FactWise attaches addenda to the original bid and tells people who saved the bid, instead of sending them a second alert.

Questions

How do I know if there is an addendum?

Check where the bid was posted (the county website or bid platform) until the deadline. Registered bidders on platforms usually get notified; others must check.

Last reviewed Oct 30, 2026. This is general information, not legal advice. Laws and thresholds change; check the current statute and the bid documents.