Guide for general contractors

How to track certificates of insurance for subcontractors

Q: What is a certificate of insurance (COI) for a subcontractor?

A certificate of insurance is a one-page summary from a subcontractor's insurer showing the policies they carry — typically general liability and workers' compensation — along with coverage limits and, most importantly, the policy expiration date. It is proof, on the day it is issued, that the subcontractor is insured.

Q: How often should I collect updated COIs from subcontractors?

Collect a fresh certificate whenever a policy renews — usually once a year per policy — and before a subcontractor starts any new job. The safest practice is to track each certificate's expiration date and request a renewal 30 days before it lapses.

Q: What happens if a subcontractor's insurance lapses on my job?

If a subcontractor is uninsured when an incident happens, the financial and legal exposure can flow up to the general contractor, and your own insurer or an auditor may deny or question coverage. A lapsed certificate is also one of the most common findings in a workers' compensation or liability audit.

Q: Is a spreadsheet good enough for tracking subcontractor insurance?

A spreadsheet works when you have only a handful of subcontractors and remember to check it. It breaks down as you add subs, because nothing reminds you before a date passes, the actual documents live somewhere else, and there is no history to show an auditor. At that point dedicated tracking software pays for itself.

If you hire subcontractors, you're on the hook for proving they're insured — not just once, but every day they're on your job. Here's how to collect, organize, and renew subcontractor certificates of insurance so nothing lapses at the worst possible moment.

By Fieldwork Studio LLC · Updated August 2026

What a certificate of insurance actually proves — and what it doesn't

A certificate of insurance (COI) is a one-page summary from a subcontractor's insurer. It lists the policies they carry — usually general liability and workers' compensation — their coverage limits, and the policy expiration dates. For a general contractor, it's the paper trail that says: on the day this was issued, this sub was insured.

The catch is in that phrase — on the day it was issued. A COI is a snapshot, not a live feed. A policy can be cancelled or simply expire the week after you filed the certificate, and the piece of paper in your folder still looks perfectly valid. That gap between "what I have on file" and "what's actually current" is the entire problem this guide is about.

Why tracking subcontractor COIs matters more than it seems

When a subcontractor is uninsured at the moment something goes wrong — an injury, property damage, a claim — the exposure doesn't stay with them. It tends to flow up to the general contractor. Your own liability and workers' comp policies can be tapped, your premiums can rise, and in a dispute you may be the one left holding it.

It also shows up at audit time. A lapsed or missing subcontractor certificate is one of the most common findings in a workers' compensation or general liability audit — and unaccounted-for subs can get reclassified as your own payroll, which gets expensive fast. Being able to show a current, complete set of certificates (and the history behind them) is what turns an audit from a scramble into a non-event.

Three ways general contractors track subcontractor insurance

1. The spreadsheet method

A row per subcontractor, columns for each policy and its expiration date. It's free and familiar, and for three or four subs it's genuinely fine.

Where it fails: a spreadsheet doesn't do anything. It won't warn you that a policy expires in two weeks, the actual certificate PDFs live in your email or a shared drive somewhere else, and once you're past a dozen subs the manual upkeep quietly slips. Most lapses happen not because someone decided to skip insurance, but because nobody was reminded in time.

2. The email-and-folder method

Request certificates by email, save the PDFs into per-subcontractor folders, and set yourself calendar reminders. Better than a spreadsheet for holding the actual documents, but the reminders are only as reliable as the person setting them, and reconstructing "what did we have on file last March?" means digging through an inbox.

3. Dedicated COI tracking software

Purpose-built tools collect the certificates, store every version, compute what's current versus expiring versus missing, and send the renewal reminders for you. This is where most contractors land once the paperwork outgrows a spreadsheet — the tool becomes the single source of truth, and chasing renewals stops being a task you have to remember.

A simple system that works no matter which tool you use

Whether you stay on a spreadsheet or move to software, the underlying system is the same five steps. Get these right and you'll never be surprised by a lapsed certificate.

List every sub and exactly what each must carry. Write down each subcontractor and the specific documents you require of them — general liability COI, workers' comp COI, trade license, W-9, and anything else your contracts or your own insurer demand.
Collect the current document and its expiration date. For every requirement, get the actual certificate and record the exact date it expires. The expiration date is the single most important field — everything else keys off it.
Set renewal reminders before the date, not on it. Give yourself a ladder — for example 30, 14, and 7 days out, then day-of — so there's time to chase a renewal before there's ever a gap in coverage.
Keep every version you've ever received. Never overwrite. When a new certificate comes in, keep the old one too, so you can always show what was on file on any given date. That history is your proof at audit time.
Be able to export the whole picture on demand. When an auditor or a client asks, you should be able to produce a current, dated list of who's compliant and who isn't in minutes, not days.

The tell that you've outgrown a spreadsheet If you've ever found out a certificate lapsed after the fact — or spent an afternoon rebuilding your compliance picture before an audit — the tracking isn't failing because you're careless. It's failing because a static list has no way to warn you. That's the moment software starts paying for itself.

How CertBunker tracks subcontractor COIs automatically

CertBunker is built to run exactly the five-step system above without you having to remember any of it. Here's how it maps:

You list your subs and their requirements — CertBunker starts you with sensible defaults (general liability COI, workers' comp COI, trade license, W-9) and you adjust from there.
Subs upload from their phone with no login. Each sub gets a private link by email — you can also copy it and text it to them yourself — and they snap a photo of the certificate and enter its expiration date. No app, no account for them to create.
You approve each upload in one click, and the compliance board turns that cell green. Every subcontractor and every required document is shown at a glance — green, expiring, or missing.
CertBunker chases renewals for you by email — 30, 14, and 7 days before a certificate expires, then day-of, to both you and the subcontractor. Each reminder sends once, so nobody gets spammed.
Every version is kept in a document repository, and the whole board exports to CSV the moment an auditor asks.

It's $75/month flat for unlimited subcontractors and documents, with a 14-day free trial and no setup fee. The first 25 companies to subscribe lock in $50/month for as long as they stay subscribed.

Stop tracking certificates in a spreadsheet you have to remember

Set CertBunker up this afternoon — list your subs, send the first request, and let it chase every renewal from here. The trial is free for 14 days.

Start your free trial

Frequently asked questions

What is a certificate of insurance (COI) for a subcontractor?

A one-page summary from the subcontractor's insurer showing the policies they carry — typically general liability and workers' compensation — with coverage limits and, most importantly, the policy expiration date. It's proof, on the day it's issued, that the sub is insured.

How often should I collect updated COIs from subcontractors?

Whenever a policy renews — usually once a year per policy — and before a sub starts any new job. The safest practice is to track each certificate's expiration date and request the renewal about 30 days before it lapses.

What happens if a subcontractor's insurance lapses on my job?

If a sub is uninsured when an incident happens, the financial and legal exposure can flow up to the general contractor, and your own insurer or an auditor may question coverage. A lapsed certificate is also one of the most common audit findings.

Is a spreadsheet good enough for tracking subcontractor insurance?

It works for a handful of subs if you remember to check it. It breaks down as you grow, because nothing reminds you before a date passes, the documents live somewhere else, and there's no history to show an auditor. That's when dedicated tracking software pays for itself.