A low bid tells you what a subcontractor is willing to charge. It tells you almost nothing about whether they can actually deliver — whether they have the crew capacity, the financial cushion, or the track record to finish your project without becoming your biggest schedule risk. Prequalification is the step that closes that gap, and it works best as a standing process applied before every award, not a one-off gut check on subs that already worry you.
Start with capacity, not just capability
A sub can be perfectly qualified on paper and still be the wrong choice for your timeline if they're already committed elsewhere. Ask directly: how many active projects are they running right now, what's their current crew size, and does that leave enough bandwidth for your schedule without pulling labor off another job mid-stream. A sub stretched across too many projects is a common, quiet cause of the delays that only surface once you're already committed.
This is also where trade-specific licensing matters — general contracting licenses don't automatically cover electrical, plumbing, or HVAC work in most states, so confirm the license on file actually matches the scope you're hiring for.
Check financial stability, not just insurance
Insurance and bonding are the baseline, but financial stability is a separate question worth asking directly: how long has the business been operating, is it in good standing with the state where it's registered, and — for larger awards — can they provide bank or credit references. A sub who can't get bonded at all, or whose bonding capacity is far below your project size, is telling you something about their financial health even on jobs where you won't require a bond outright.
Verify safety record on anything beyond small residential work
For commercial, multifamily, or any project with real safety exposure, ask for OSHA recordable incident rates (EMR — experience modification rate) and whether they've had any citations in the past three years. A sub with a clean license and solid pricing but a poor safety record is a liability that shows up in your insurance premiums and your schedule the first time there's an incident on site.
Ask questions that reveal process, not just credentials
- How do you handle a schedule conflict when two clients need you the same week?
- Walk me through how you price and approve a change order.
- Who is the actual crew lead on my project — not the estimator who bid it?
- What happens if a key employee or foreman leaves mid-project?
- Can you provide three references from projects similar in size and scope to this one?
Build it into a repeatable scorecard
Ad hoc prequalification — a phone call here, a reference check there — doesn't scale once you're awarding work regularly, and it's inconsistent from one project manager to the next. A simple scorecard (license/insurance status, bonding capacity, safety record, reference check, current capacity) applied the same way every time turns prequalification into a repeatable filter instead of a judgment call made under deadline pressure.
Weight the scorecard by project risk, not a fixed formula
Not every category deserves equal weight on every project. A small tenant-improvement job with a modest budget doesn't need the same bonding scrutiny as a ground-up commercial build, and a trade with low safety exposure (interior finishes, for example) doesn't need the same OSHA-record scrutiny as structural steel or excavation. Set the weighting once per project type — residential, light commercial, ground-up commercial, public/government — rather than re-deciding it on every award, and prequalification stays fast without becoming a rubber stamp.
Document the decision, even when it's obvious
When a sub clearly passes every check, it's tempting to skip writing anything down. Do it anyway — a short record of what was verified and when protects you if a dispute or claim comes up later, and it builds an internal history you can reuse the next time that same sub bids. Over a few years, this record becomes its own asset: a bench of subs with documented performance, not just a list of names.
Re-verify on long projects, not just at award
Licenses expire, insurance policies lapse, and a sub's financial position can change over the course of a multi-month or multi-year project. For anything longer than a few months, build a reminder to re-check license and insurance status partway through — it costs a few minutes and catches the gap before it becomes a claim, rather than after.
Where verification data can do the first pass for you
Every subcontractor listed on Sub-Finder already carries independent verification — license, business registration, and identity checks run against Cobalt Intelligence, OpenSOSData, and Didit, with a fourth trade-license check where applicable — so the licensing and business-standing piece of prequalification is done before you ever make first contact. That leaves your own scorecard to focus on the parts only a conversation can surface: capacity, references, and fit for your specific project.
FAQ
**How long should prequalification take?** For a routine award to a known trade, a scorecard review should take fifteen to twenty minutes once the sub has supplied documentation. Larger or unfamiliar subs justify more time — reference calls in particular are worth the extra day.
**Should prequalification be different for a repeat sub versus a new one?** Yes — a documented, positive history with a sub is itself part of the record. Re-verify credentials are current, but you don't need to re-run the full process from zero on every award to a proven sub.