What Is a Substitute Form W-9?
A substitute Form W-9 is a customized version of the official IRS Form W-9 that businesses can use to collect taxpayer identification numbers (TINs) and required tax certifications from U.S. payees. The IRS permits substitute Forms W-9 provided they contain substantially similar information to the official form and satisfy applicable certification requirements.
Substitute Forms W-9 can be incorporated into supplier onboarding documents, account opening forms, and other business processes. However, businesses must ensure that the required certifications, signature provisions, and taxpayer instructions comply with IRS guidance.
Key takeaway: Substitute Forms W-9 offer flexibility for tax documentation collection, but they must meet IRS requirements and be reviewed when official form revisions are introduced.
Substitute W-9 Checklist
| Requirement | What businesses should verify |
|---|---|
| Substantially similar content | Required taxpayer information matches the applicable official W-9 |
| Certification language | All applicable certifications are included and correctly presented |
| Signature requirements | Certifications and consent language meet IRS rules |
| FATCA exemption | Relevant exemption code and certification are handled correctly |
| Instructions | Required instructions are available to payees |
| Electronic submission | Identity authentication, record integrity and electronic signature rules are met |
| Form revision monitoring | Templates are reviewed when IRS guidance changes |
What changed?
Although nothing changed, sometimes it is important to review the rules and confirm that everything continues to be in compliance. Forms W-9 are probably one of the more widely requested withholding certificates. One part that is somewhat new, but continues to be a bit confusing, are the Foreign Account Tax Compliance Act exemption codes. This article walks through a refresher of the rules and how to manage some of these awkward issues.
Payors and withholding agents are allowed to use their own Forms W-9, which are not the official Internal Revenue Service (IRS) published Forms W-9. These forms are called substitute Forms W-9. In order to be sure that the substitute Form W-9 is reliable, a few items must be in place.
What Are the IRS Requirements for a Substitute Form W-9?
The content and wording of the substitute form must be substantially similar to the official IRS Form W-9. Once the IRS publishes an updated revision, it is important to review the new revision for any additions, wording changes or deletions that must be included in the substitute, so that it has substantially similar content.
Incorporating the substitute form with other forms or documents.
It is acceptable to incorporate a substitute Form W-9 with other business forms and documents that are used customarily. This includes bank account signature cards, subscription documents, vendor agreements, and other onboarding types of documentation.
What FATCA Certifications Must a Substitute Form W-9 Include?
This requirement is the most important! The certifications on a substitute Form W-9 must clearly state that under penalties of perjury:
- The payee’s taxpayer identification number is correct,
- The payee is not subject to backup withholding due to failure to report interest and dividend income,
- The payee is a U.S. person
- The FATCA code entered on the form (if any) indicating that the payee is exempt from FATCA reporting is correct.
It is this last certification that is a little awkward. What if a payor only makes payments of amounts subject to withholding under chapter 3 (non-resident alien withholding and reporting) and no withholdable payments under chapter 4 (FATCA)? The substitute form rules tell us that if a payor or withholding agent is not collecting a FATCA exemption code, it can omit that field from the substitute Form W-9 and may notify the payee that item 4 does not apply. But, what does this mean? Is it okay to omit the FATCA exemption code all together and tell the payee not to worry about Item 4 in the certification? Does this boarder on providing tax advice? This gets hairy when using an electronic Form W-9 and having to request authentication for each certification. We have some precedent and standards for pre-FATCA electronic Forms W-8BEN, but not as much for Forms W-9. This is something to consider when implementing electronic withholding certificates and substitute Forms W-9. Watch for our upcoming article on electronic withholding certificates!
What Instructions Must Accompany a Substitute Form W-9?
Payors and withholding agents using a substitute form must provide the Form W-9 instructions to the payee only if the payee requests them. An exception to this rule is where the IRS has notified the payee that backup withholding applies. In this case the payor or withholding agent must instruct the payee, either orally or in writing, to strike out the language in the certification that relates to underreporting. Here, the words ‘defined below’ in the certification can be replaced with ‘defined in the instructions’ for item 3 of the Certification on Form W-9 when the instructions will not be provided to the payee except upon request.
When providing instructions on a substitute Form W-9, be sure that they are in a manner similar to the official form.
What Are the Signature Requirements for Substitute Forms W-9?
If using a separate signature line that is only for the certifications, then the certifications must be stated clearly.
If using a single signature line for the required certifications and other provisions contained in the document, then:
- The certifications must be highlighted, boxed, printed in bold-face type, or presented in some other manner that causes the language to stand out from all of the other information on the substitute form.
- Immediately above the signature line, the following statement must be included and must stand out in the same manner as the certifications in the first bullet: “The Internal Revenue Service does not require your consent to any provision of this document other than the certifications required to avoid backup withholding.”
Do not use a substitute Form W-9 that requires the payee, by signing, to agree to provisions unrelated to the required certifications.
Do not imply that a payee may be subject to backup withholding unless the payee agrees to provisions on the substitute form that are unrelated to the required certifications.
How to Implement?
Payors and withholding agents choosing to use a substitute Form W-9 should consider the following:
- Keep checking for new IRS revisions to Form W-9 to confirm that the substitute is substantially similar to the official IRS version.
- If using an electronic Form W-9, confirm that it is compliant with the rules for substitute forms and electronic receipt of Forms W-9.
- Confirm that your instructions to any substitute Forms W-9 are compliant with the rules for providing instructions.
- Never alter the certifications unless explicitly allowed in the rules or IRS guidance. • Update process and procedure manuals to incorporate any changes required.
- Update training materials and presentations to staff.
- Confirm your process and procedure manual includes an approach to call back and replace any documents that contain a substitute Form W-9 when changes are required, such as account opening forms.
Resources
Instructions to the Requestor of Form W-9
Rev. Proc. 83-89,1983-2 C.B. 613; amplified by Rev. Proc. 96-26, which is on page 22 of Internal Revenue Bulletin 1996-8 at IRS.gov/pub/irs-irbs/irb96-08.pdf.
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Frequently Asked Questions About Substitute Forms W-9
A substitute Form W-9 must contain substantially similar information to the official IRS Form W-9 and meet applicable certification requirements. These include taxpayer identification details, required certifications under penalties of perjury, and appropriate signature provisions. Businesses should follow the IRS Instructions for the Requester of Form W-9 when developing or updating substitute forms.
Yes. The IRS permits businesses to create customized substitute Forms W-9 for collecting taxpayer identification information and certifications. These forms can be incorporated into vendor onboarding documents, bank account applications, and other business forms, provided they satisfy IRS requirements.
Yes. Substitute Forms W-9 may be collected electronically if the system meets applicable IRS requirements. These include maintaining the integrity of submitted information, authenticating the person submitting the form, retaining appropriate records, and obtaining a valid electronic signature when required.
Yes, in certain circumstances. If a business does not collect a FATCA exemption code, the IRS permits that field to be omitted from a substitute Form W-9. The payee must be notified that the corresponding FATCA certification does not apply. Businesses should review the applicable IRS instructions before modifying certification language.
Businesses should review their substitute Forms W-9 whenever the IRS publishes a revised official form or updated instructions. This helps ensure that the substitute form continues to contain substantially similar information and satisfies applicable certification requirements. Changes to taxpayer classifications, certification language, or reporting requirements may necessitate updates.
The June 2026 draft requester instructions introduce a proposed fifth certification relating to certain U.S. digital asset brokers. The draft also explains how substitute Forms W-9 that omit this certification would be treated. Organizations should assess the potential impact on their substitute forms while continuing to follow currently applicable IRS requirements until the revised guidance is finalized.
Updated: October 2026
