To fill out a W-9 for an S corp, enter the corporation’s legal name on Line 1, leave Line 2 blank unless you use a DBA, check the “S corporation” box on Line 3a, skip Line 3b, enter exempt payee code 5 on Line 4, add your mailing address on Lines 5 and 6, put your nine-digit EIN in Part I, and have an authorized person sign Part II. The whole form takes about five minutes. The trap is that small errors on the classification line or the EIN can trigger backup withholding at 24% of every payment your business receives, so it’s worth going slowly. Work from the current form: the March 2024 revision changed several line numbers and added a new Line 3b, so download a fresh copy from irs.gov before starting.
Line 1: The Corporation’s Legal Name
Put the corporation’s legal name here, spelled exactly as it appears on your federal tax returns. For a standalone S corporation, that’s the name the IRS has on file from when you obtained your EIN and filed Form 2553 to elect S corp status. Abbreviations or misspellings that don’t match IRS records cause a name/TIN mismatch. The IRS flags the mismatch to the payer through a “B-Notice,” and backup withholding can follow.
Line 2: Trade Name or DBA
If the corporation operates under a different name than its legal name, put that trade name here. It helps the payer reconcile records when they know you by your public-facing name. If the legal name and operating name are the same, leave Line 2 blank.
Line 3a: Federal Tax Classification
Line 3a lists seven checkboxes. If your business was formed as a corporation under state law and then elected S status, check the box labeled “S corporation” and nothing else. That tells the payer you’re a pass-through entity for federal income tax purposes, which affects whether a 1099 is required at year-end.
If You’re an LLC Taxed as an S Corp
Many small businesses are formed as LLCs but elect S corporation tax treatment by filing Form 2553. If that’s you, don’t check the “S corporation” box. Instead, check the box labeled “LLC” and then write the letter “S” in the tax classification space next to it. The letter tells the payer that even though you’re an LLC under state law, you follow S corporation tax rules.1Internal Revenue Service. Instructions for the Requester of Form W-9
Skipping that “S” is one of the most common mistakes on the form. Without it, the payer may assume the LLC is taxed as a partnership or a disregarded entity, and the resulting 1099 reporting can come out wrong.
Line 3b: Skip It
The March 2024 revision added Line 3b, which asks about foreign partners, owners, or beneficiaries. It applies only to partnerships, trusts, estates, and LLCs classified as partnerships. An S corporation, including an LLC taxed as an S corp, skips Line 3b.2Internal Revenue Service. Form W-9 (Rev. March 2024)
Line 4: Exemption Codes
Line 4 has two fields: an exempt payee code and a FATCA reporting code.
For the exempt payee code, corporations (including S corporations) fall under code 5 on the W-9’s exemption chart. Entering “5” tells the payer that your corporation is exempt from backup withholding on most payment types.2Internal Revenue Service. Form W-9 (Rev. March 2024) One exception: for broker transactions involving securities, S corporations don’t qualify for the exempt payee code, so leave that field blank in that specific context.
For the FATCA reporting code, most S corporations are treated as “specified U.S. persons” and are not exempt from FATCA reporting. Leave the field blank or write “N/A” unless your corporation falls into a narrow category listed in the form instructions, such as a bank, registered securities dealer, or tax-exempt organization.1Internal Revenue Service. Instructions for the Requester of Form W-9
Lines 5 and 6: Address
Line 5 takes the street address or P.O. box. Line 6 takes the city, state, and ZIP code. Use the address where you receive official tax mail, and make sure it matches what the IRS has on file. If you’ve moved recently and haven’t updated your address with the IRS, do that first so notices don’t get lost.
Part I: Employer Identification Number
Part I asks for your nine-digit EIN. Federal law requires every person furnishing tax information to provide a proper identifying number, and for any entity that isn’t an individual, that means an EIN.3Office of the Law Revision Counsel. 26 USC 6109 – Identifying Numbers Don’t substitute the owner’s Social Security Number. It’s the wrong number for an incorporated entity and causes reporting problems downstream.
If your corporation doesn’t have an EIN yet, apply for one through the IRS website before submitting the W-9. Don’t turn in the form with a placeholder or an SSN while you wait.
Part II: Certification and Signature
Part II is where an authorized person signs the form under penalty of perjury. The signature certifies four things: the TIN you provided is correct, your business isn’t subject to backup withholding (or is exempt from it), your business is a U.S. person, and any FATCA codes you entered are accurate.
The backup withholding certification is where people slip. By signing, you’re certifying that the IRS hasn’t notified you that you’re subject to backup withholding due to underreporting. If you have received such a notice, cross out that part of the certification before signing. Signing without crossing it out is the piece with real legal risk.
Providing false information on a W-9 can carry criminal penalties under federal law: fines up to $100,000 for individuals or $500,000 for corporations, plus up to three years of imprisonment.4Office of the Law Revision Counsel. 26 USC 7206 – Fraud and False Statements Prosecutions for W-9 fraud are rare in practice and generally involve deliberate schemes rather than honest mistakes. Still, the perjury language on the form is there for a reason.
Whether Your S Corp Will Even Get a 1099
This surprises many S corp owners: payers are generally not required to issue a 1099-NEC or 1099-MISC for payments made to an incorporated business. The IRS exempts payments to corporations from most information return reporting.5Internal Revenue Service. Am I Required to File a Form 1099 or Other Information Return? The W-9 is still necessary because the payer needs it to confirm your entity type and document why no 1099 was issued.
Payers must still issue a 1099 to corporations, including S corps, in a few situations:
- Attorney fees of $600 or more paid to a law firm or legal service provider get reported on Form 1099-NEC regardless of corporate status.
- Payments for medical and healthcare services get reported in Box 6 of Form 1099-MISC.
- Gross proceeds paid to attorneys, such as settlement payments routed through a law firm, get reported on Form 1099-MISC even when the law firm isn’t the ultimate recipient.
If your S corp doesn’t provide legal or medical services, your clients likely won’t file a 1099 for your payments. They still need the W-9 on file to document that decision.6Internal Revenue Service. Instructions for Forms 1099-MISC and 1099-NEC (04/2025)
What Happens When the Form Is Wrong
When the name and EIN on your W-9 don’t match IRS records, the consequences follow a predictable sequence.
First, the payer must begin backup withholding at 24% of every reportable payment.7Internal Revenue Service. Publication 15 (2026), (Circular E), Employer’s Tax Guide The payer also sends you a “First B-Notice” with a blank W-9. Send back a properly completed replacement and the withholding stops.8Internal Revenue Service. Backup Withholding “B” Program
If the same mismatch shows up a second time within three years, the payer sends a “Second B-Notice.” A corrected W-9 alone won’t stop backup withholding at that point. You’ll need to request Letter 147C from the IRS to verify your name and EIN, and provide that letter to the payer.8Internal Revenue Service. Backup Withholding “B” Program
Payers also face their own IRS penalties for filing information returns with incorrect or missing TINs.9Internal Revenue Service. Information Return Penalties Those charges hit the payer, not you, but payers who get hit with them tend to become very persistent about collecting corrected forms.
When to Send an Updated W-9
A W-9 doesn’t expire, but certain changes require you to send a fresh form to every payer that has the old one on file:
- A corporate name change, merger, or new EIN assignment.
- A change in tax classification, such as revoking your S election and becoming a C corporation, or a C corporation newly electing S status.2Internal Revenue Service. Form W-9 (Rev. March 2024)
- A change in exempt payee status, if you previously claimed to be an exempt payee and that no longer applies.
An address change alone doesn’t technically require a new W-9, but sending one anyway prevents misrouted 1099s at year-end.
Submitting the Form Securely
The completed W-9 contains your EIN, which is sensitive information. Don’t send it as an unencrypted email attachment. The IRS permits electronic submission, including by fax, as long as the system verifies the identity of the sender and can produce a hard copy on request.10Internal Revenue Service. Instructions for the Requester of Form W-9 Many payers offer secure portals or encrypted file-sharing for this. Physical mail works too. Whichever route you use, keep a copy of what you submitted so you can match it against any 1099 that arrives next January.