A COI is usually generated by your insurance carrier or a 3rd party associated with the carrier (Accord, etc.) and forwarded via fax and/or mail to the requesting party. It will be a statement of policies in effect by you regarding one or more of the following items:
1. General and/or Commercial Liability Insurance - in case you or your employees cause damage to their equipment, property, etc.
2. Workmen's Compensation Insurance - to cover any employee you may bring to work there in case they are injured.
3. General Auto Insurance - in case the brakes fail on your truck & you run into something - or somebody.
It will show the policy numbers, issue & expiration dates, and limits of liability for each type.
Our company almost has to have a full time person checking this on all our subcontractors to make sure it's up to date. It's a hassle, but without it the IRS may be liable for damages. We wouldn't want Uncle Sam to spend any money on
this, now.
Face it - it's their show, they make the rules.