A W-9 request letter is the short written notice a business sends to a vendor, contractor, landlord, or other payee asking them to complete IRS Form W-9 and return it before payments start. Its job is narrow: get the payee’s legal name and taxpayer identification number on file so you can issue accurate 1099s at year-end and avoid having to withhold 24% from every check in the meantime. Keep it brief, specific, and dated.
When To Send It
Send the letter as soon as you engage anyone you reasonably expect to pay $600 or more during the calendar year for services, rent, prizes, or other reportable amounts. That $600 figure is the point at which you must file an information return, typically Form 1099-NEC for non-employee compensation or Form 1099-MISC for rents and similar payments.1Internal Revenue Service. Form W-9 Request for Taxpayer Identification Number and Certification2Office of the Law Revision Counsel. 26 USC 6041 – Information at Source3Office of the Law Revision Counsel. 26 US Code 6041A – Returns Regarding Payments of Remuneration for Services and Direct Sales
Don’t wait until payments approach the threshold. If there is a reasonable chance you’ll cross it, request the W-9 before the first check goes out. The usual recipients are independent contractors, consultants, attorneys, landlords, and unincorporated service providers.
Corporations are generally exempt from 1099 reporting for most payment types, with important exceptions: payments to attorneys, medical and health care payments, and payments for services made by federal executive agencies are reportable even when the payee is a corporation.4Internal Revenue Service. Instructions for the Requester of Form W-9 Because of those exceptions, many companies request a W-9 from every new vendor, corporate or not, and keep it on file.
What To Include in the Letter
The letter should cover a small set of essentials clearly enough that the recipient knows what to do and why.
- Your company name and a plain-language statement of purpose: you are collecting the W-9 for federal tax reporting on payments made in the course of business.
- What you need back: a completed IRS Form W-9, current revision March 2024. Attach a blank copy or link to the current version on irs.gov.5Internal Revenue Service. About Form W-9, Request for Taxpayer Identification Number and Certification
- A firm deadline. Ten to fifteen business days is standard. State that a late or missing response can trigger backup withholding at 24%.
- Return instructions: exactly how to send the completed form back, whether that is a secure email portal, a fax number, or a mailing address.
- A named contact with phone and email for questions.
Specify the revision date. The IRS updates the form periodically, and an outdated version may lack the current perjury certification language, which can make the submission invalid.
Guidance To Include for Common Errors
Most rejected or mismatched W-9s go wrong in the same places. A few lines of instruction in the letter save weeks of follow-up.
Name and TIN Matching
The name on Line 1 must match the name associated with the TIN the payee enters. For individuals and sole proprietors, that is the name on the Social Security card. A different business name goes on Line 2. For LLCs and other entities, the legal name on the entity’s tax return goes on Line 1. Mismatches here are the leading cause of B-notices from the IRS later on.
LLC Tax Classification
Line 3 confuses LLCs more than any other field. A single-member LLC that has not elected corporate treatment is a disregarded entity: the owner’s name goes on Line 1, the LLC name on Line 2, and the owner’s tax classification is checked on Line 3a. Multi-member LLCs and those that elected corporate status check the LLC box on Line 3a and enter the classification code (C, S, or P).4Internal Revenue Service. Instructions for the Requester of Form W-9
Exempt Payees
Certain payees, including tax-exempt organizations, government entities, corporations, and registered securities dealers, are exempt from backup withholding for most payment types and enter an exempt payee code on Line 3b. Collect the completed W-9 even when the payee is exempt, so the exemption is documented.4Internal Revenue Service. Instructions for the Requester of Form W-9
Foreign Payees Get a Different Form
Form W-9 is only for U.S. persons: citizens, resident aliens, and domestic entities. Note in the letter that foreign payees should not complete a W-9 and should contact you to determine which W-8 series form applies. Form W-8BEN is used by foreign individuals to certify foreign status and claim reduced withholding under an applicable tax treaty.6Internal Revenue Service. About Form W-8 BEN, Certificate of Foreign Status of Beneficial Owner for United States Tax Withholding and Reporting (Individuals) Form W-8BEN-E is the entity version. Form W-8ECI applies when a foreign person’s income is effectively connected with a U.S. trade or business. Sending a W-9 to a foreign payee wastes time and can lead to incorrect withholding; the default rate on payments to foreign persons is 30%, versus 24% for backup withholding on U.S. persons without a valid TIN.
Electronic and Substitute Versions
You aren’t required to send the paper IRS form. The IRS allows requesters to set up electronic systems to collect W-9 information, including by fax. The system must provide the same information as the paper form, verify the identity of the person submitting it, require an electronic signature under penalties of perjury using the same language as the paper form, and be able to produce a hard copy on IRS request.7Internal Revenue Service. Instructions for the Requester of Form W-9
A substitute W-9, with your branding or built into a vendor onboarding portal, is acceptable as long as it is substantially similar to the official form.1Internal Revenue Service. Form W-9 Request for Taxpayer Identification Number and Certification It must collect the same data fields (name, business name, tax classification, TIN, address) and carry the same certification and perjury statement. Strip any of those out and the form is no longer acceptable.
Sending the Request Securely and Tracking It
A completed W-9 carries a Social Security number or employer identification number, so treat it like any sensitive financial document. Encrypted email portals are the practical choice for most businesses: fast, auditable, and protected in transit. If you send the request by physical mail, certified mail with return receipt gives you proof of delivery, which matters if the IRS later questions your effort to collect the information.
Log the date sent, the delivery method, and the response status for each vendor. A dedicated spreadsheet or an accounts-payable flag for outstanding W-9s catches missing forms long before filing season.
What Happens If the Payee Doesn’t Respond
If you don’t have a valid TIN for a reportable payee, federal law requires backup withholding at a flat 24% from all reportable payments to that person.8Internal Revenue Service. Backup Withholding C Program IRC Section 3406 makes you personally liable for the tax if you fail to withhold.9Office of the Law Revision Counsel. 26 US Code 3406 – Backup Withholding The withheld amounts go on the payee’s 1099 so they can claim credit for the withholding on their own return. Once the payee finally provides a valid W-9, stop withholding within 30 days.10Internal Revenue Service. Backup Withholding for Missing and Incorrect Name/TINs
There are also per-return penalties under IRC Section 6721 for filing information returns with missing or incorrect TINs, scaling by how quickly the error is fixed, up to $340 per return if corrected after August 1 or never filed, and $680 per return with no annual cap for intentional disregard (amounts for returns due in calendar year 2026).11Internal Revenue Service. 20.1.7 Information Return Penalties You can request a waiver by demonstrating reasonable cause under IRC Section 6724, which turns on whether you took affirmative steps to get the correct information.12Office of the Law Revision Counsel. 26 USC 6724 – Waiver; Definitions and Special Rules This is why the letter, follow-ups, and delivery records matter. A business that can show it sent timely requests and followed up on non-responses has a real reasonable-cause argument. One reconstructing the effort after a notice arrives does not.
The IRS also offers a free TIN Matching service that lets you verify name-and-TIN combinations before filing information returns, interactively or in bulk through the e-Services portal.13Internal Revenue Service. Taxpayer Identification Number (TIN) Matching Running a match when a W-9 arrives catches errors while the vendor is still easy to reach.
How Long To Keep the Letter and the Form
The IRS doesn’t set a standalone retention period for W-9s. The general rule is to keep records supporting items on your tax return until the period of limitations expires: at least three years from filing, and six years if you omitted more than 25% of gross income.14Internal Revenue Service. How Long Should I Keep Records For employment tax records, the IRS says at least four years after the tax becomes due or is paid.15Internal Revenue Service. Topic No. 305, Recordkeeping A W-9 supports the information return you file for that payee, so holding it for at least four years after the related 1099 is a reasonable floor. Keep the request letter with it. That letter is what proves you asked.