Does a Certificate of Insurance Actually Protect You at Your Workers’ Comp Audit?
5 min read · Updated June 6, 2026
Short answer: only if it’s the right certificate, covering the right dates. A COI sitting in a folder doesn’t automatically keep a subcontractor off your workers’ comp audit. Auditors look at three things.
1. Is there a workers’ comp line?
Many certificates show general liability but no workers’ comp. GL does not exclude the sub from your WC audit. If the WC box is blank, the auditor can treat the sub as your payroll.
2. Are the limits adequate?
The coverage has to meet your policy’s and your state’s requirements. A token policy that doesn’t meet minimums can be disregarded.
3. Do the dates cover the whole job?
This is the one that bites good contractors. The COI’s effective-to-expiration window has to span the entire period the sub worked for you. Two common failures:
- Coverage started after the sub began working — the early days are uncovered, and chargeable to you.
- Coverage expired before the job ended (or was cancelled for non-payment mid-project) — the tail is chargeable to you.
A certificate you collected in March doesn’t prove coverage for work done in January, and it doesn’t prove the policy wasn’t cancelled in June.
So what actually protects you?
Verification and timing, not just possession. Collect the COI before the first payment, confirm the WC line and limits, and re-collect whenever it expires while the sub is still working. Match it against the dates you actually paid them.
You can pressure-test any sub in under a minute: open the free COI Gap Checker →. Enter the work dates and the COI dates, and it tells you exactly whether you’re protected or exposed — and why.
Doing this for 20 subs across a year
Checking one sub by hand is easy. Tracking dozens of certificates against dozens of payment periods, catching every mid-project lapse, is the part that breaks down — and creates the surprise bill. That’s what we’re automating. Get early access to the automated version →
Frequently asked questions
Does a certificate of insurance protect me at a workers’ comp audit?
Only if it’s the right certificate for the right dates — it must show a workers’ comp line, adequate limits, and coverage spanning the entire period the sub worked.
Does general liability insurance exclude a sub from my audit?
No. General liability doesn’t count for workers’ comp. The certificate must show a workers’ comp line specifically.
What if a sub’s COI expired mid-job?
The uncovered tail is chargeable to you. Re-collect a current certificate whenever coverage lapses while the sub is still working.
See your own exposure — free
Two free tools, no signup: estimate your audit surprise, and check whether your subs’ COIs actually protect you.
Related guides
How to Read a Certificate of Insurance (ACORD 25) Like an Auditor
A certificate of insurance packs a lot into one page. Here’s how to read an ACORD 25 the way an auditor does — and the lines that decide whether a sub is covered.
6 min read · Read →Certificate Holder vs. Additional Insured: What Contractors Actually Need
“Certificate holder” and “additional insured” are not the same thing, and confusing them leaves you exposed. Here’s what each means and what to ask subs for.
5 min read · Read →How to Collect (and Actually Track) Certificates of Insurance from Subcontractors
Collecting a certificate once isn’t enough — you have to track it against work dates and renewals. Here’s a simple system contractors can run, and how to automate the nagging.
6 min read · Read →