Vendor paperwork gets confusing because everyone throws around abbreviations like W-9, COI, certificate holder, additional insured, and vendor agreement. If you are a contractor or property manager, you do not need to be a lawyer to understand the basic purpose of each document.
A W-9 helps with tax/vendor setup, a COI shows insurance coverage, and a vendor agreement explains the work/business relationship. They are different documents and should not be mixed together.
Simple comparison
| Document | What it is | Why it matters |
|---|---|---|
| W-9 | Tax form with legal name and taxpayer identification info | Helps the company set up vendor payments and tax reporting |
| COI | Certificate of Insurance | Shows current insurance coverage and policy dates |
| Vendor agreement | Contract or service terms | Explains responsibilities, payment terms, scope, and rules |
What property managers should check
- Does the vendor name match across documents?
- Is the W-9 complete and readable?
- Is the COI current?
- Are required coverage types listed?
- Is additional insured wording needed?
- Is the agreement signed if required?
- Are expiration dates in the tracker?
What contractors should do
- Keep a clean PDF copy of your W-9.
- Request updated COIs before old ones expire.
- Ask exactly what wording the property needs on the COI.
- Use one consistent legal business name.
- Send documents before the job day, not after.
Common mistake
A COI is not the same thing as a contract, and a W-9 does not prove insurance. Each document answers a different question.
Disclaimer
This is a plain-English operational guide, not legal, tax, or insurance advice. For specific requirements, property managers and contractors should confirm with their accountant, attorney, or insurance agent.
Final thought
Clean paperwork makes approval easier. When documents are current, consistent, and organized, everyone wastes less time chasing basics.
Need vendor paperwork cleaned up?
If COIs, W-9s, expiration dates, licenses, and vendor folders are scattered everywhere, DamnJobs can help organize the mess.