Top 5 best ITB software for construction in 2026

ITB software sends invitations to bid to your subcontractors and tracks who is bidding. Every tool on this list does that. Where they differ is everything around it: how big a network they bring, how much the sub has to do to respond, and how much of preconstruction they try to own.

Here are the five worth looking at in 2026, what each is best for, and a table to compare them. Details come from each vendor's own website and help docs as of September 2026, so confirm anything that matters with the vendor.

What to look for in ITB software

Before the list, the five things that decide most choices:

• Your own sub list. Can you bring in your existing spreadsheet and organize it by trade or CSI division without a week of cleanup?
• Friction for the sub. If a sub has to create an account or log in to a portal, fewer of them respond. Smaller trades feel this most.
• Who the email comes from. An invite from a name the sub knows gets opened more than one from a platform address.
• Response tracking. You want a clear bidding or not bidding answer per contact, plus who has looked at the invite.
• Scope of the platform. Some tools only do invitations. Others add leveling, prequalification and a public network. Pay for the part you will use.

The 5 best ITB software tools for construction

1. Invite All: best for inviting subs you already know

Invite All does one job well. You pick the trades on a scope from your own directory, write the email once with placeholders, and it sends a personal, tracked invitation to every contact from your own Microsoft 365 or Google Workspace mailbox. The emails land in your Sent Items and replies come to your inbox. Each sub gets a private link with the drawings and Bidding / Maybe / Not bidding buttons. No account, no portal.

You see delivered, clicked, viewed and answered for every contact, rolled up by scope. Contacts already invited to a scope are locked so nobody gets a double invite.

It leaves out the public network, bid leveling and prequalification on purpose. If your subs are people you already work with and you want more of them bidding, start here.

2. Downtobid: best for AI plan reading

Downtobid's standout feature is AI that reads your plans, finds the scopes and drafts scope notes, then sends personalized invites from your own email. Subs don't need a login to view the invite, and silent subs get automatic reminders as the due date gets close. It also has its own network, which Downtobid puts at 57,000+ verified subcontractors.

A good fit for GCs who spend a lot of time breaking drawings into scopes before they can even send an invite.

3. BuildingConnected: best for a large sub network

BuildingConnected is Autodesk's bid management platform. Autodesk says its network has 1.5M+ construction professionals, the biggest on this list. It includes bid leveling, and prequalification through TradeTapp.

The tradeoff is that it runs as a platform. Invites come from a BuildingConnected address, and subs need an account to see project details and respond. Best for GCs who bid outside their home market and need to find new subs. More on BuildingConnected alternatives.

4. SmartBid: best for bid management plus prequal

SmartBid, now part of ConstructConnect, covers invitations, an online plan room, side by side bid comparison and subcontractor prequalification. It shows you when subs open your emails and download documents, and subs can be given access to keep their own contact details current, which helps keep your list clean.

A solid pick for mid-size and larger GCs who want a full bid management tool and access to ConstructConnect's network. How iSqFt, SmartBid and ConstructConnect fit together.

5. Procore Bid Management: best if you already run projects in Procore

Procore Bid Management lives inside Procore, so bidding sits in the same system you run projects in. It handles invitations, Will Bid / Will Not Bid responses, bid leveling and subcontractor risk analysis. Invites are sent from Procore. Bidders can reply to the invite email with their bid attached, though Procore recommends they log in to submit.

Procore charges by product based on your annual construction volume, so it is an expensive way to send invitations if you don't use the rest of Procore. How Procore prices bid management.

ITB software comparison table

Which ITB software should you choose?

• You mostly invite the same trusted subs: Invite All. Simple, sends from your inbox, and subs never need an account.
• Breaking down plans eats your week: Downtobid.
• You need to find new subs in new markets: BuildingConnected or SmartBid.
• You want leveling and prequal in the same tool: BuildingConnected, SmartBid or Procore.
• Your company already runs on Procore: Procore Bid Management.

A quick test helps. Look at your last ten projects and count how many subs were not already in your list. If that number is small, you are paying for a network you don't use, and a simpler tool will likely get you more responses for less money.

FAQ

What is ITB software?

ITB stands for invitation to bid. ITB software lets a general contractor send bid invitations to subcontractors by trade, share drawings, and track who is bidding, who is not, and who hasn't answered. How to write a good invitation to bid email.

Is there free ITB software for construction?

PlanHub has a free plan for GCs, and some teams still use Outlook mail merge with a spreadsheet. Both work. With mail merge you give up tracking and a clean record of who was invited. How to mail merge bid invitations from Outlook.

Do subcontractors need an account to respond to an ITB?

It depends on the tool. Invite All and Downtobid let subs respond from a link with no account. BuildingConnected needs a free account to see project details. Procore lets bidders reply by email but recommends logging in. Do subcontractors need an account to bid?

How do I get more subs to respond to my ITBs?

Send from a name they know, keep it short, make responding one click, and follow up two or three days before the due date. Why subs don't respond to bid invitations.