This is the form a business asks a contractor or supplier to complete before paying them, so it can report those payments correctly later.
It is short and it is filled in wrongly often enough to cause real problems, usually around the name and classification of the entity being paid. A mismatch there surfaces months later as a notice.
This covers what the form is for, who supplies it and who collects it, how each line should be completed, the errors that come up most often, and what happens when it is incomplete or wrong.
What Is Form W-9?
IRS Form W-9, Request for Taxpayer Identification Number and Certification, is provided by a payee to a payer to supply the payee's TIN (Social Security Number or EIN) and certify the payee's tax status. The payer uses the information to correctly complete and file Form 1099 at year-end.
This form carries a taxpayer identification number, so where it is stored matters as much as whether it was collected. It belongs in restricted storage rather than an email folder, and it should be checked against the payee record in your accounting system at the point of collection.
Anu Gupta, CA, EA, B.Tech · LinkedInWho Provides a W-9?
- Freelancers and independent contractors providing their SSN or EIN to clients.
- Businesses providing their EIN to vendors, suppliers, or customers who will pay them.
- Landlords providing their TIN to tenants who pay commercial rent.
- Investors providing their TIN to banks, brokers, or borrowers.
Line-by-Line Completion Guide
Line 1: Name
Enter your legal name exactly as it appears on your tax return. For individuals, this is your personal name. For single-member LLCs disregarded for tax purposes, enter the OWNER'S name (not the LLC name) on Line 1.
Line 2: Business Name / DBA
If you do business under a different name (DBA, 'doing business as'), enter it here. This line is for the business name when Line 1 is the individual's name. Leave blank if same as Line 1.
Line 3: Federal Tax Classification
This is the most critical line and the most common source of errors. Check the box that describes the entity for tax purposes:
| Tax Classification | When to Check |
|---|---|
| Individual/sole proprietor | Self-employed person with no formal entity, or single-member LLC disregarded for tax purposes |
| C Corporation | Corporation taxed as a C-corp |
| S Corporation | Corporation with an S-election in effect |
| Partnership | Multi-member partnership or LLC taxed as a partnership |
| Trust/estate | Trust or estate receiving payments |
| Limited liability company | Check this AND enter the tax classification: P (partnership), C (C-corp), or S (S-corp) in the box |
| Other | Rare, nonprofit organizations, government entities |
Line 4: Exemptions
Most individuals and small businesses leave Line 4 blank. Exemptions apply to:
- Exempt payee code: for entities not subject to backup withholding (e.g., corporations are generally exempt from 1099-MISC reporting in many cases, enter code 5 for C-corps).
- FATCA exemption code: for entities exempt from FATCA reporting requirements.
Lines 5 and 6: Address
Enter the address where you want correspondence sent. This is typically your business address.
Part I: Taxpayer Identification Number
Enter EITHER your SSN (for individuals and sole proprietors) OR your EIN (for businesses). Not both. Rules:
- Individual filing as an individual (including single-member LLC disregarded): use your SSN.
- Entity with its own EIN (corporation, partnership, multi-member LLC): use the EIN.
- If you do not yet have an EIN but have applied, write 'Applied For' in the space, backup withholding may still apply until you provide a TIN.
Part II: Certification / Signature
By signing, you certify that:
- The TIN provided is correct.
- You are not subject to backup withholding (or you are exempt).
- You are a US person (US citizen, resident alien, or domestic entity).
- The FATCA code entered (if any) is correct.
Common Errors and How to Avoid Them
| Mistake | Correct Approach |
|---|---|
| Single-member LLC checking the LLC box | Check 'Individual/sole proprietor' if the LLC is disregarded; use LLC box only if you have elected corporate/partnership status |
| Using business name on Line 1 for a disregarded entity | Use the individual owner's name on Line 1; put the LLC name on Line 2 |
| SSN vs EIN mismatch | Use SSN for disregarded entities; EIN for corporations and multi-member LLCs |
| Leaving Line 3 blank | Always check a tax classification box |
| Not signing Part II | The W-9 is not valid without a signature |
What Happens If the W-9 Is Incomplete or Incorrect?
- The payer may be required to withhold 24% of payments as backup withholding and remit to the IRS.
- You may face issues matching your 1099s to your tax return.
- Resubmit a corrected W-9 as soon as possible.
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Frequently Asked Questions
Is Form W-9 filed with the IRS?
No. Form W-9 is given to the payer and kept in their records. It is NOT sent to the IRS. The payer uses it to prepare Form 1099 at year-end, which IS filed with the IRS.
How long should a payer keep a W-9?
Payers should retain W-9s for at least 4 years after the last filing year they were used.
I am a non-US person. Do I fill out Form W-9?
No. Non-US persons (foreign individuals and entities) should use the W-8 series of forms instead (W-8BEN for individuals, W-8BEN-E for entities).
My LLC has two members. Which form do we use?
A multi-member LLC taxed as a partnership uses Form W-9, Line 3 checked as 'Limited liability company' with 'P' in the box for partnership. Use the LLC's EIN.
What should a business do with these once collected?
Store them securely and use them, which sounds obvious and is where the process usually breaks. The form contains a taxpayer identification number, so it belongs in restricted storage rather than in an email folder or a shared drive everyone can read. It should also be checked against the payee record in the accounting system at the point of collection, since a mismatch between the two is what produces a notice later.
Written by
Anu Gupta, CA, EA, B.Tech
Anu works with US businesses on tax and entity questions at Profitjets, from choosing a structure to the filings that follow it. She writes about the decisions owners make once and then live with for years. Connect on LinkedIn
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