How to send an addendum to bidders so every sub actually gets it

Here's the failure that everyone in estimating has either lived through or heard about from the person who did. A late addendum lands, maybe day 16 of a 20-day bid, and it adds real scope to one of the major trades. The low mechanical bidder priced off the original set. They never went back to the plan room, why would they, nobody told them to. The GC carries their number. The GC wins. And then the first month of the job is spent arguing about who pays for the difference between what was priced and what was drawn.

The addendum was posted. Nobody disputes that. It just wasn't received, and those turn out to be very different things.

Posting is not the same as notifying

It's worth being clear about why, because "but it was on the plan room" feels like it should be a defence.

Platform notifications get filtered. They arrive from a domain the sub never asked to hear from and they land in Other, or Promotions, or Junk, depending on the mail client. Some subs have long since trained themselves to ignore anything from that domain.

Downloading the drawings once doesn't subscribe anyone to anything. Plenty of subs pull the set on day two, save it locally, and price from that copy for the rest of the bid. They aren't checking for updates. They're estimating.

And "everyone" isn't a list. If the original invitation went out by Bcc and the addendum went out through the plan room, you have two recipient lists that don't match, and no way to know who fell through the gap between them.

What to do instead

Know who's still in

Per scope, you need every person who got the original invitation and where they stand right now: bidding, maybe, not bidding, or silent. Everyone except "not bidding" gets the addendum. Yes, including the ones who never answered. Silence isn't a decline, and sometimes an addendum that clarifies scope is the thing that tips a silent sub into bidding.

If your tracking can't produce that list in about a minute, that's the real problem, and it's worth fixing the tracking before the next round rather than during this one.

Send it to each person, from you

Same channel the invitation used. An email from your name to their name, with the original subject line plus "Addendum 2" tacked on. Subs find things by searching the project name in their inbox, so keep the project name where it was.

One email per person. Not because it's polite (though it is) but because individual emails are the only thing you can actually track. A Bcc tells you nothing about who got what. If you're doing this by hand, mail merge makes it bearable.

Say what changed for their trade

You don't owe every trade a summary of a thirty-page addendum. But for the major scopes, one line is worth a lot:

Addendum 2 affects electrical: the panel schedule on E4.01 changed and exterior lighting was added on the west parkade. Bid date unchanged.

A sub who reads that knows in five seconds whether they need to re-price. A sub who gets "Addendum 2 has been issued, see attached" has to open the PDF and hunt through it to find out, and some of them, being busy, won't.

Ask them to confirm

End with something like "please confirm you've received this," and then keep track of who does. That's the whole step. It seems small. It isn't.

Follow up the ones who don't, next day

Email is fine for most of the list. For the trades your bid genuinely depends on, phone.

Check acknowledgments on bid day

Every proposal's cover page should list the addenda. When one doesn't, call before you use the number. It's a thirty-second call and it has saved a lot of people a lot of money.

If the addendum moves the bid date

Then it isn't really an addendum notice anymore. It's the most important email of the whole round, and it should be treated that way: new date in the subject line, sent individually, and a personal phone call to every "bidding" sub on the major trades. A sub who turns up with a number on the old date because they missed the change is a damaged relationship, and for nothing.

What your tracking should be able to tell you

Per addendum, four things. Who was sent it. Who has opened it, if your tool can see that. Who has confirmed. And who is marked "bidding" but hasn't confirmed, because that last group is tomorrow morning's phone list.

In a spreadsheet this is a column per addendum, which works, if someone fills it in. Invite All sends an addendum to everyone on a scope from your own mailbox, with the same per-contact tracking as the original invitation (delivered, clicked, viewed), so the "who hasn't seen this" question has an answer without anyone maintaining a column. Whichever way you do it, the question you need to be able to answer in under a minute is: does every bidding mechanical sub know about the added scope? Yes or no.

The short form, for the wall

Everyone invited on the affected scopes, minus "not bidding." One email each, from you, same subject line plus the addendum number. One line on what changed for their trade. Ask for confirmation. Chase the ones who don't confirm the next day, and phone the ones you need. And before you use any number on bid day, check that the proposal acknowledges the addenda.