How to Write Clear Bid Addenda for Public Procurement: A Step-by-Step Guide for Agencies

Best Practices for Creating Contractor-Friendly Amendments That Reduce Bid Errors and Streamline Public Construction Projects

By Joanne Branch

A structured approach to writing addenda can eliminate confusion, minimize bid irregularities, and help contractors submit accurate proposals, saving your agency time and reducing protest risk.

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Writing Clear, Tight, and Easy-to-Use Addenda for Public Bids

When an active public bid requires updates, the addendum you issue must be clear, easy to apply, and simple for vendors and contractors to use. Contractors often “slipsheet” addenda, literally inserting revised pages into their bid documents, or cut and paste updated text into their working copies.

The smoother and more precise your addendum is, the less chance there is for errors in the bids you receive and evaluate.

A well-structured addendum not only corrects or updates the bid documents but also helps ensure that every bidder interprets your intent the same way. Whether your vendors are new to public work or seasoned professionals, clarity and specificity keep the playing field level.

The Four Actions in Any Addendum

Almost everything you need to communicate in an addendum falls into one of four categories. Using these terms explicitly sets expectations and gives bidders clear directions on what to do.

• Adding – Introducing entirely new information that was not previously issued.

• Appending – Adding onto something that already exists, such as extending a paragraph or adding a subsection.

• Replacing – Removing an issued paragraph, page, or section and substituting a revised version in its entirety.

• Clarifying – Offering information when there isn’t a specific place in the documents to edit, but something needs to be explained or corrected.

Most addendum items can, and should, use one of these action words to instruct bidders precisely. If you find yourself doing more than one action (for example, replacing a paragraph and clarifying a related point), create separate numbered items. Clear separation reduces confusion and preserves the addendum as an easy-to-navigate working document.

Start with the Bid Documents First

To write solid and user-friendly addenda, begin by going back to the issued bid documents. Read them as if you were going to write the addendum text directly into the pages. This approach naturally guides you to the paragraphs, pages, or sections that need modification. Capture the exact location, section number, paragraph number, and page number, as this becomes the anchor point for your addendum item.

This step also helps you verify the scope of the change: Do you truly need to replace the entire section, or is appending a sentence sufficient? Does the clarification belong in an existing paragraph, or is it stand-alone? Let the structure of the original documents inform how you craft each addendum entry.

Aim for Precision, Brevity, and Usability

A good addendum is not long; it is precise. Each item should follow a simple pattern:1. Reference the exact location in the bid documents.2. Identify the action (Add, Append, Replace, or Clarify).3. Provide the new or revised text, word-for-word.

Avoid broad descriptions like “modify as needed” or “revise accordingly.” Contractors cannot act on vague instructions. The more literal and direct your language, the cleaner the results when they integrate the addendum into their bid set.

Supporting Better Bids Through Better Addenda

At its core, an addendum is a communication tool. A clear and well-organized addendum reduces bidder questions, minimizes the risk of bid irregularities, and helps contractors deliver accurate pricing. By focusing on structure, precision, and usability, you support both your internal team and your vendor community, and ultimately contribute to a more efficient and fair public bidding process.

(sample addendum)

AGENCY NAME

BID #                  BID TITLE

ADDENDUM # __

DATE

The following is issued to supplement or revise bid Documents. The revisions to the documents are described below. Unless specifically changed by this addendum, the remainder of the drawings, documents, and specifications remain in effect as originally issued.

REVISIONS:

Existing:  Bid submittal date: Wednesday, July 23, 2025 on or before 2:00 PM

Change to:  Bid submittal date: Wednesday, July 30, 2025 on or before 2:00 PM

CLARIFICATIONS:

RFI Question: How many coats of paint are required on this project?

RFI Answer: As stated in existing bid documents, a base coat plus two (2) coats of paint are required for a total of three (3) coats.

DRAWINGS:

Existing:  Page A7 – Library Reading Room Design

Replace with:  Replace with Page A7(a) – Library Reading Room Design as attached

ADDITIONAL INFORMATION:

Owner Provided, Contractor Installed (OPCI) two-page listing attached to summarize OPCI items noted on drawings included in bid packet.