Free Vendor Onboarding Checklist for Small Businesses (2026)
Onboarding a new vendor sounds simple until the first time it bites you. The contractor whose insurance lapsed mid-project. The freelancer you can't 1099 because you never got their W-9. The supplier whose ACH info got changed by a phishing email. The "great deal" vendor who turned out to be on a sanctions list.
A vendor onboarding checklist isn't bureaucracy — it's the cheapest insurance you'll ever buy. Here's the full version, with templates you can copy.
The 10-item vendor onboarding checklist
Before you pay any new vendor a single dollar, collect:
1. W-9 form (US vendors)
What: IRS Form W-9 with vendor's legal name, business name, address, tax classification, and TIN/EIN.
Why: Required to issue 1099-NEC at year-end for any vendor you pay $600+ in a calendar year. Missing W-9s = either you fail to issue 1099s (IRS penalty) or you withhold backup withholding (annoying for the vendor and an admin burden for you).
When: Before the first payment, every time. No exceptions.
2. Certificate of Insurance (COI) — for service vendors
What: Proof of vendor's general liability, professional liability, and workers' comp insurance.
Why: If their employee gets hurt on your property or their work damages something, their insurance covers it — not yours. Without a COI, you're potentially on the hook.
Required coverage minimums (typical):
- General liability: $1M per occurrence / $2M aggregate
- Workers' comp: as required by state
- Professional liability (for consultants, designers, accountants): $1M
Critical: COIs expire. Track expiration dates and require renewal. About half the small businesses we see have at least one expired COI on file for an active vendor.
3. Banking information (for ACH payments)
What: Routing number, account number, account type (checking/savings), bank name, account holder name.
Why: To pay them via ACH instead of check.
Critical: Verify banking info via phone call to a known number, not via email. Email-based banking changes are the #1 vector for vendor invoice fraud. The pattern: someone hacks the vendor's email, sends you "updated banking info" before a real invoice arrives, you pay the wrong account, the money is gone.
4. Signed contract or master service agreement
What: Terms of the relationship — scope, pricing, payment terms, termination conditions, confidentiality, IP ownership, indemnification.
Why: When something goes wrong, you'll need a written agreement. "We agreed in an email" is rarely enough.
Minimum for small purchases: A simple PO with terms on the back is fine for one-time, low-risk purchases.
5. Payment terms
What: Net 15, Net 30, Net 60, due on receipt, etc.
Why: Affects your cash flow planning. Most small businesses default to Net 30 — push for that. For new vendors with concerning credit profiles, ask for Net 15 or Due on Receipt.
6. Business license / registration verification
What: Confirmation the vendor is a legitimate registered business.
Why: Quick check via your state's Secretary of State website (free, takes 30 seconds). Confirms the entity exists and is in good standing.
For higher-risk vendors: Pull a Dun & Bradstreet report or check Better Business Bureau ratings.
7. Sanctions/watchlist screening (for international or high-value vendors)
What: Confirmation the vendor isn't on the OFAC SDN list or other sanctions lists.
Why: Federal law prohibits doing business with sanctioned entities. Penalties are severe.
How: Free check at sanctionssearch.ofac.treas.gov. Takes 60 seconds. Document that you checked.
8. References (for new high-value vendors)
What: Two or three customer references, verified by phone.
Why: A great vendor on paper can be a nightmare in practice. References surface this before you commit.
When to require: For vendors over a meaningful spend threshold (often $25K+ annually) or for critical functions (IT services, accounting, legal).
9. Single point of contact
What: Name, email, phone, and role of the primary contact at the vendor.
Why: Communication breakdowns are the #1 source of vendor friction. Knowing who to call when something goes wrong matters.
Bonus: Ask for a backup contact in case primary is out.
10. Internal: Cost-center / GL coding assignment
What: What account does this vendor's spend get coded to? What cost center / department / project?
Why: Decided once at onboarding. Consistently applied forever. Saves your bookkeeper from making this judgment call invoice-by-invoice.
Vendor onboarding form template
Here's a copy-able form you can send to every new vendor:
[Your Company] — New Vendor Onboarding
Welcome! Before we can process your first invoice, please provide the following:
Business information
- Legal business name:
- DBA (if applicable):
- Business address:
- Type of entity (LLC, S-corp, etc.):
- State of incorporation:
- Years in business:
- Website:
Contacts
- Primary contact name:
- Primary contact email:
- Primary contact phone:
- Backup contact:
- AR/billing contact (if different):
Tax & payment
- W-9 attached: [yes/no]
- Preferred payment method: [ACH / Check / Card]
- Banking info (will be verified by phone): [routing, account, bank]
- Payment terms requested: [Net 15 / Net 30 / Net 60 / Other]
Insurance (for service vendors)
- COI attached: [yes/no]
- GL policy expiration date:
- Workers' comp expiration date:
- Professional liability expiration date (if applicable):
Compliance
- Authorized to do business in [your state]: [yes/no]
- Currently on any sanctions or restricted lists: [no — confirm in writing]
References (if requested)
- Reference 1 (name, company, phone):
- Reference 2 (name, company, phone):
Save it as a PDF or web form. Send it to every new vendor. No exceptions.
The "small purchases" exception
Realistically, you won't run this whole checklist for every $200 vendor purchase. Here's the practical tiering:
Tier 1 — Card purchases under $500 from established retailers (Amazon, Costco, Office Depot):
- No onboarding needed. Use a card.
Tier 2 — Vendors you'll pay $500–$5,000/year:
- W-9 (always)
- Banking info if paying by ACH
- Single point of contact
Tier 3 — Vendors you'll pay $5,000+/year OR who do work on your premises:
- Full checklist above
This tiering keeps friction low for one-off purchases while protecting you on the relationships that matter.
Tracking and renewing
Onboarding is once. Maintenance is forever. You need:
- A vendor record with all the docs attached, easily searchable
- Expiration reminders for COIs (auto-email vendor 30 days before expiration)
- Annual W-9 refresh if anything has changed (new address, new TIN)
- Banking re-verification annually or any time the vendor sends a "change request"
A good purchase approval system handles vendor records as a built-in feature, not a separate spreadsheet.
Red flags to walk away from
Some vendors are not worth onboarding. Walk away if:
- They refuse to provide a W-9
- They can't produce a current COI
- They request unusual payment terms (full payment upfront for services)
- Their references can't be reached or won't speak on the phone
- They've changed banking info more than once via email
- They're brand new, unknown, and pushing for fast onboarding
- Their business address is a residential address with no other indicators of legitimate operation
The opportunity cost of a bad vendor far exceeds the cost of saying no.
How Becision helps
Becision tracks vendors, COI expiration dates, payment terms, and approval rules per vendor. When a request comes in for a vendor with an expired COI, the system flags it before approval. Saves you the embarrassing call to your subcontractor explaining why you can't pay them this week. Free for small teams. Try it →
Common questions
Q: How often should I refresh vendor info? COIs: per their expiration. W-9s: annually if anything has changed (new address, new entity name, new TIN). Banking: re-verify any time the vendor requests a change.
Q: What if a vendor refuses to provide a W-9? You're required to do backup withholding (24% of payment) and remit it to the IRS. Most vendors comply once they understand this — it's not a power move on your part, it's federal tax law.
Q: Do I need an MSA for every vendor? For one-time small purchases, no — a PO with terms is fine. For ongoing relationships, recurring services, or any vendor doing work on your property: yes.
Q: What about international vendors? They get a W-8BEN (or W-8BEN-E for entities) instead of W-9. Plus more rigorous sanctions screening. Plus possible tax withholding. It's worth talking to your accountant before onboarding international vendors.