# Vendor onboarding checklist: the documents to collect before the first payment [Home](/) / [Document guides](/documents) / Vendor onboarding checklist By [Arthur Teboul](/authors/arthur-teboul), Founder, DokuTrak. Published 2026-10-30, updated 2026-10-30. > **In brief:** A vendor onboarding checklist lists what accounts payable collects before paying a new vendor: a registration form, a signed Form W-9 or W-8, a certificate of insurance, verified bank details, the contract, and a sanctions check. Each item has an owner, a date received and, where it expires, a renewal date. ## What is a vendor onboarding checklist? Onboarding is the step between choosing a vendor and paying it. **A vendor master record** is the entry in your accounting system that holds the vendor’s legal name, tax ID, remit-to address, bank details and payment terms. Every document on this list feeds that record or proves something in it. Collect the tax form first. Form W-9 is how a U.S. vendor gives you the correct tax ID you need for information returns ([IRS, About Form W-9](https://www.irs.gov/forms-pubs/about-form-w-9)). Without it, you may have to withhold from payments, so the form comes before the first invoice is paid. If you are still weighing whether a vendor is safe to use, run the vendor due diligence checklist first. This page assumes the choice is made. ## Who sends it, and when The vendor fills in the registration form and signs the tax form. Its insurance broker issues the certificate of insurance, and its bank issues the bank letter or the voided check. Accounts payable or procurement collects everything, runs the checks, and creates the vendor in the accounting system once each line is complete. ## Where to get a vendor onboarding checklist 1. Send the vendor the request email with your registration form and a blank Form W-9. 2. Run the name and TIN through IRS TIN Matching if you file information returns. 3. Ask the vendor to have its broker send a certificate of insurance. 4. Confirm the bank details by phone, on a number you already hold. 5. Screen the vendor on OFAC’s sanctions list, then create the record and log renewal dates. ## Wrong files people send instead - Paying the first invoice before the W-9 arrives. - A W-9 with a trade name on the first line instead of the legal name. - Bank details changed by email with no call-back to a known number. - A certificate of insurance that expired the month after onboarding, with no reminder set. - A foreign vendor sent a W-9 when it should complete a W-8 form. ## The checklist, document by document Work down the table in order. The last column is the check accounts payable runs before ticking the line, such as a phone call to confirm bank details. | Document | Issued by | Check before you accept it | | --- | --- | --- | | Vendor registration form | Vendor | Legal name, DBA, entity type, remit-to address, AP contact | | Form W-9 (U.S. vendor) | Vendor | Signed, legal name on the first line, TIN present | | Form W-8BEN or W-8BEN-E (foreign vendor) | Vendor | Right form for an individual or an entity | | TIN Matching result | IRS e-Services | Name and TIN combination matches | | Certificate of insurance | Vendor’s insurance broker | Your company as holder, limits meet the contract, dates current | | Bank letter or voided check | Vendor’s bank | Account owner matches the legal name; confirmed by phone | | Business or professional license | State or local agency | Active, with expiry noted | | Signed contract or purchase order terms | Both parties | Payment terms and scope match the record | | NDA or data processing agreement | Both parties | Signed before the vendor sees client data | | Sanctions screen | You, on OFAC’s search | No match, with date and result saved | ## Tax forms, backup withholding and year-end 1099 forms A foreign individual gives you Form W-8BEN when you ask for it ([IRS, About Form W-8BEN](https://www.irs.gov/forms-pubs/about-form-w-8-ben)). A foreign company uses Form W-8BEN-E to document its status ([IRS, About Form W-8BEN-E](https://www.irs.gov/forms-pubs/about-form-w-8-ben-e)). **Backup withholding** is tax a payer must hold back from a payment when the payee has not given a correct tax ID. The IRS sets it at the current rate of 24 percent ([IRS, Backup withholding](https://www.irs.gov/businesses/small-businesses-self-employed/backup-withholding)). Collecting the W-9 before the first payment avoids it. Flag each vendor for year-end reporting when you create it, for example with the 1099 box it falls under. For 2025 payments, the 1099-NEC line was $600 ([IRS, Instructions for Forms 1099-MISC and 1099-NEC (Rev. 2025)](https://www.irs.gov/pub/irs-prior/i1099mec--2025.pdf)). For tax years beginning after 2025, the threshold for reporting certain payments rose to $2,000 ([IRS, Instructions for Forms 1099-MISC and 1099-NEC](https://www.irs.gov/instructions/i1099mec)). Before you file, payers in the IRS Payer Account File can check name and TIN combinations through TIN Matching ([IRS, Taxpayer Identification Number (TIN) Matching](https://www.irs.gov/tax-professionals/taxpayer-identification-number-tin-matching)). Our guide to [collecting W-9 forms from vendors](/blog/collect-w9-from-vendors) covers the chase. ## Bank details: the step fraudsters target **Payment redirection fraud** is a scam in which someone posing as a vendor asks you to send payments to a new account. The defense is a habit, not a tool: - Take bank details only on a bank letter or voided check, never in an email body. - Call the vendor on a phone number already in your records, not one in the request. - Apply the same call-back to every later change of bank details. - Have a second person release the first payment to a new account. ## Sanctions screening, insurance and renewals OFAC says the assets of Specially Designated Nationals are blocked and U.S. persons are generally prohibited from dealing with them ([OFAC, Frequently Asked Questions: Sanctions List](https://ofac.treasury.gov/faqs/topic/1631)). Search the vendor’s legal name on OFAC’s Sanctions List Search and save the result with the date ([OFAC, Frequently Asked Questions: Sanctions List](https://ofac.treasury.gov/faqs/topic/1631)). For insurance, send a [certificate of insurance request](/documents/certificate-of-insurance-request) and log each policy’s expiry. Ask for a fresh W-9 when a vendor changes its name, entity or tax ID, and a new certificate at each renewal. ## The template: New vendor setup request email Send this to a vendor you have chosen, with your registration form attached. Delete the NDA line if the vendor will not see client data. Subject: Vendor setup for [Your company]: forms needed before [date] ```text Hi [Client name], Welcome aboard. To set you up for payment, please send by [date]: - The attached vendor registration form, completed. - A signed Form W-9 with your legal business name, or Form W-8BEN-E if your company is outside the U.S. - A bank letter or voided check for the account we should pay. We will call [vendor phone on file] to confirm it. - A certificate of insurance from your broker naming [Your company] as certificate holder. - The signed NDA, since you will see client files. We can pay your first invoice once these are in. Thank you, [Your name] ``` ## Questions people ask ### What documents do you need to onboard a new vendor? A registration form, a signed Form W-9 or W-8, a certificate of insurance, a bank letter or voided check, the contract or purchase order, and any license the work needs. Add an NDA when the vendor sees client data. ### What happens if a vendor never returns a W-9? You may have to withhold from its payments. The IRS sets backup withholding at the current rate of 24 percent when a payee has not given a correct tax ID ([IRS, Backup withholding](https://www.irs.gov/businesses/small-businesses-self-employed/backup-withholding)). ### Which vendors need a Form 1099-NEC? Generally, unincorporated vendors you pay for services, plus law firms even when incorporated. The line was $600 for 2025 payments ([IRS, Instructions for Forms 1099-MISC and 1099-NEC (Rev. 2025)](https://www.irs.gov/pub/irs-prior/i1099mec--2025.pdf)). For tax years beginning after 2025, nonemployee compensation of $2,000 or more is reported ([IRS, Instructions for Forms 1099-MISC and 1099-NEC](https://www.irs.gov/instructions/i1099mec)). ### Should I screen vendors against the OFAC list? Yes, it is a quick search. OFAC says U.S. persons are generally prohibited from dealing with listed persons, and its Sanctions List Search tool lets you check a name ([OFAC, Frequently Asked Questions: Sanctions List](https://ofac.treasury.gov/faqs/topic/1631)). **Not advice.** This page is general information, not tax, legal or HR advice. Rules change: check the cited source and ask your own professional before you rely on it. Last reviewed October 25, 2026. ## Sources - [IRS, About Form W-9](https://www.irs.gov/forms-pubs/about-form-w-9): Form W-9 is used to provide a correct TIN to the person who must file an information return with the IRS, for example to report income paid. - [IRS, About Form W-8BEN](https://www.irs.gov/forms-pubs/about-form-w-8-ben): A foreign person gives Form W-8BEN to the payer when requested, whether or not claiming a reduced rate of, or exemption from, withholding. - [IRS, About Form W-8BEN-E](https://www.irs.gov/forms-pubs/about-form-w-8-ben-e): Form W-8BEN-E is used by foreign entities to document their status for chapter 3 and chapter 4 purposes. - [IRS, Backup withholding](https://www.irs.gov/businesses/small-businesses-self-employed/backup-withholding): A payer may be required to withhold at the current rate of 24 percent when the payee failed to provide a correct TIN for the required information return. - [IRS, Instructions for Forms 1099-MISC and 1099-NEC](https://www.irs.gov/instructions/i1099mec): For tax years beginning after 2025, nonemployee compensation of $2,000 or more goes in box 1a of Form 1099-NEC, the threshold may be adjusted for inflation from 2027, and the corporate exemption does not apply to payments for legal services. - [IRS, Instructions for Forms 1099-MISC and 1099-NEC (Rev. 2025)](https://www.irs.gov/pub/irs-prior/i1099mec--2025.pdf): For 2025, nonemployee compensation of at least $600 is reported on Form 1099-NEC, and rents and other income of at least $600 on Form 1099-MISC. - [IRS, Taxpayer Identification Number (TIN) Matching](https://www.irs.gov/tax-professionals/taxpayer-identification-number-tin-matching): TIN Matching lets payers that file information returns validate TIN and name combinations before filing, interactively or in bulk, after applying through IRS e-Services. - [OFAC, Frequently Asked Questions: Sanctions List](https://ofac.treasury.gov/faqs/topic/1631): SDNs’ assets are blocked and U.S. persons are generally prohibited from dealing with them; the full list can be browsed with OFAC’s Sanctions List Search tool. ## More on this topic - [Collecting W-9 forms from vendors](/blog/collect-w9-from-vendors) - [W-9 guide](/documents/w-9) - [TIN checker](/tools/tin-checker) - [Document collection for bookkeepers](/for/bookkeepers) - [EIN Verification: Check a Vendor’s EIN With the IRS](/letters/ein-verification) ## About the author Arthur Teboul (Founder, DokuTrak) is building DokuTrak after watching professionals lose hours chasing clients for documents over email. [Arthur Teboul](/authors/arthur-teboul). How this page was made (methodology): it is built from the primary sources listed under Sources, and every rule and figure on it links to the source it comes from. Last updated October 25, 2026. Spotted an error or a rule that changed? [Contact us](/contact). ## Ask once. DokuTrak does the chasing. - Your client uploads from one link, with no account and no password. - Reminders go out on a schedule, by default 2, 5, 10 and 14 days after the request, until the file arrives. - You accept every file or mark it for re-upload, and your client gets the note by email. The AI never accepts a file. 14-day free trial, no card. Add one only to keep going. [Request these documents with DokuTrak](https://app.dokutrak.com/sign-up?docs=w-9%2Cvoided-check%2Ccontract%2Cinvoice)