Hiring subcontractors is half the job of running a general contracting operation, and it's the half nobody teaches you. You can price a $200K renovation down to the penny, but if the electrical sub ghosts you mid-rough-in, that number stops helping.
The problem is the process. Hiring subs who show up, carry proper insurance, and won't blow up your schedule takes more than "vet your subs and sign a contract." This article covers where to find subs, what to verify before hiring a subcontractor, how to review bids, what paperwork to collect, and how to build enough bench strength to keep taking on work.
Sourcing: Where General Contractors Actually Find Reliable Subs
Sourcing is the first bottleneck in subcontractor hiring. A general contractor who starts calling for a plumber the same week rough-in needs to happen on a $180K bath remodel is already late, and every decent mechanical sub in the market already has a two-week look-ahead full of someone else's work.
The best subs usually come from peer referrals, not cold outreach. A non-competing general contractor running similar-sized work can point you toward a framing crew, roofing sub, or concrete sub who actually answers the phone. Supply houses are another underused channel: your lumber yard and electrical counter staff see which subs are buying consistently, paying on time, and keeping crews busy. That pattern tells you more about a sub's construction cash flow than any online profile.
Beyond referrals, state licensing boards offer searchable databases that confirm active licenses. Industry groups like your local HBA or AGC chapter put you in rooms with subs who invest in their own businesses. Labor shortages make all of this more urgent. When options are thin, the contractor with an existing relationship usually gets the call back first.
A $2M general contractor bidding four projects a quarter needs sourcing to run as a background process, not a scramble when a timeline is already locked. Block time monthly to collect names, check licenses, and make introductions with no active scope attached. Keep a running list in your PM software or a shared spreadsheet so the whole team can add and reference contacts.
Compliance: What to Verify Before Hiring a Sub
Compliance risk carries the biggest downside in subcontractor hiring. A drywall sub's workers' comp policy lapses mid-project, one of their guys falls off a scaffold, and your GL carrier may end up fielding the claim because the sub's coverage wasn't active.
Before any sub mobilizes on your jobsite, verify five things in this order:
Active state license: Check the state licensing board database yourself. An expired or wrong-classification license can void your liability coverage on that scope.
COI from the carrier: Get it sent directly from the sub's insurance company, not from the sub. Confirm you're listed as additional insured.
Workers' comp coverage: Verify the policy is active for the classification of work being performed.
EMR score: The Experience Modification Rate tells you how the sub's safety record compares to their industry average. Anything above 1.0 means more claims than typical; anything above 1.3 deserves hard questions.
References on problem handling: Call two general contractors the sub has worked for and ask one specific question: how did the sub handle a problem on your job? Anyone can finish clean work.
For subs taking on larger scopes like roofing, HVAC, electrical, and structural, contractors commonly add financial prequal: two years of financial statements, current backlog, and bonding capacity.
Calendar every expiration date across every active sub. A workers' comp policy that lapses on March 15 while that sub's crew is still on your jobsite creates a gap you won't know about until something goes wrong. Set a 30-day reminder before each expiration and require the sub to provide a renewed COI before the old one runs out. No current COI, no access to the site.
Bid Review: How to Spot Red Flags in Subcontractor Bids
Bid reviews are where most hiring mistakes happen, because the lowest number is almost never the best number. A general contractor reviewing three bids for a $45K electrical scope on a light commercial fit-out sees $42K, $46K, and $38K. The $38K bid looks like savings, but more often it's a sub who missed scope, underestimated labor, or plans to make up the difference on change orders.
The first red flag is a bid that's more than 15% below the others without a clear explanation. The sub either misread the plans, excluded work you assumed was included, or is buying the job to keep the crew busy and then cutting corners to stay solvent. Ask for a scope breakdown. If they can't explain what's included and excluded line by line, walk.
Vague scope language is just as dangerous. "Electrical per plans" sounds complete, but it leaves every gray area open for dispute. Who pulls the permit? Who supplies temp power? Who handles low-voltage? A sub who won't put carve-outs in writing either hasn't thought it through or is counting on billing you extras later.
Watch for a sub who pushes back on your contract template. Experienced general contractors use their own sub agreement with flow-down provisions, pay-when-paid language, back-charge rights, and spend controls for materials. A sub who insists on their own contract is removing protections you need. Scarcity doesn't mean you skip due diligence on who you're handing a scope to.
Documentation: The Subcontractor Hiring Checklist Every General Contractor Needs
Documentation issues create disputes at the end of a job. A general contractor closes out a $250K renovation only to discover the tile sub never signed a lien waiver on their third progress payment. Now there's a potential mechanic's lien on the homeowner's property, and the sub has already moved on.
A consistent onboarding process prevents this. Before the sub's crew shows up on day one, collect and file these items:
Signed sub agreement using your template, with scope, flow-down provisions, payment terms, and back-charge language.
W-9 for year-end 1099 reporting. Collect this before the first payment, not in January when you're chasing paperwork.
COI and workers' comp verification as described above, with expiration dates calendared.
Partial conditional lien waiver template agreed upon in advance, signed with every progress payment.
Safety acknowledgment confirming the sub's crew will comply with your jobsite safety standards and OSHA requirements.
Contact sheet with the sub's project lead, office contact, and emergency number.
Lien waiver tracking only works if you know exactly what's been paid and when. Keeping sub payments in a dedicated account—rather than running everything through a single operating account—makes it easier to match payments to waivers and catch any gaps before closeout.
Scheduling: How to Build a Sub Bench You Can Scale With
Schedule risk keeps general contractors from taking on more work when the sub bench is too thin. If your electrical sub is already stretched across four active jobs, you can't bid a fifth with much confidence. One industry workforce survey found that 80% of firms with open electrician positions found them hard to fill, and the numbers for carpenters, plumbers, and other crafts were also steep.
The fix is depth, not just quality. You need at least two prequalified subs per trade, ideally three for your highest-volume scopes. That means running the full vetting process on backup subs before you need them, keeping their documentation current as described above, and giving them occasional smaller scopes to maintain the relationship. The same applies whether you're hiring subcontractors for roofing scopes, mechanical rough-ins, or finish trades.
After every project, run a simple evaluation: Did the sub hit their schedule milestones? Were there punch list callbacks? Did they handle change orders professionally or turn every field directive into a billing dispute? Track this in a spreadsheet or your PM software. The general contractors who keep the best sub rosters treat this data like a hiring record, not a post-mortem. When a new project comes in and you need a mechanical sub, you're not starting from scratch. You're pulling up notes from the last three jobs and calling the sub who hit milestones and handled the change order without turning it into a billing fight.
Payment reputation matters here too. Contractors commonly report that subs prioritize general contractors who pay on time, and in a tight labor market, a Profit First setup for separating sub payment money from operating money can make it easier to keep preferred subs working with you.
Keep Sub Payments Tight and Visible
The general contractors who keep projects moving usually aren't relying on luck. They've built a hiring process that catches bad fits early, an onboarding process that keeps paperwork tight, and a sub bench deep enough to cover schedule gaps when one trade gets stretched thin. Just as important, they make it easier to pay the right people on time because committed sub money isn't mixed in with everything else.
Relay lets you open up to 20 checking accounts1 with no monthly maintenance fees, so you can separate sub payments, materials, and tax reserves instead of tracking it all in one pile. Open an account to keep sub payments on time and job costs visible across every project.
Relay is a financial technology company and is not an FDIC-insured bank. Banking services provided by Thread Bank, Member FDIC. FDIC deposit insurance covers the failure of an insured bank. Certain conditions must be satisfied for pass-through deposit insurance coverage to apply.
Frequently Asked Questions
How Do I Find Subcontractors in a Tight Labor Market?
Peer referrals carry the most weight: ask general contractors running comparable work who they'd hire again. Supply house staff and local trade association contacts round out the list. The sourcing section above covers each channel in detail.
What Insurance Should I Verify Before Hiring a Sub?
General liability, workers' comp, and an EMR score review are the minimum. The critical step is having the carrier send the COI directly to you rather than accepting a copy from the sub. See the compliance section above for the full verification sequence.
Should I Use the Sub's Contract or My Own?
Yours. Flow-down provisions, back-charge language, and payment terms need to come from your template. Handing that control to a sub's contract creates gaps you'll find at the worst time.
How Many Backup Subs Should I Keep Per Trade?
Aim for two to three who've already been through your full vetting process. The schedule risk section above covers how to keep those backups active and engaged between projects.
What's the Biggest Red Flag in a Subcontractor Bid?
A number 15% or more below the pack with no scope explanation attached. That gap usually means missed work, underestimated labor, or a plan to recover through change orders. The bid risk section above breaks down what to look for line by line.
Do I Need Lien Waivers From Every Sub on Every Payment?
Every progress payment gets a partial conditional waiver; final payment gets a final unconditional waiver clearing all lien rights. Skipping this process leaves the homeowner's property exposed to mechanic's liens and puts you in the middle.
