IRS Form W9 is similar to the Form W-4  that is used for employees, but does not lead to withholding.
What is a W9 Form?
Form W-9 is used to request a tax identification number and other information that can later be used to populate tax forms such as 1099s .
When do you Use a W9 Form?
Business Owners and other people who hire independent contractors use the Form W-9 to collect the contractor’s information. Independent contractors who are US Citizens or resident aliens fill out a Form W-9, while others may fill out a Form W-8. The IRS W9 is also used to collect information from trusts, estates and corporations who receive income from a business.
Financial institutions may also request the completion of Form W-9, and you may have to fill out an IRS Form W9 for mortgage interest  paid, acquisition or abandonment of secured property, cancellation of debt  or contributions to an IRA.
Requesting a Form W9
If you need someone to fill out a Form W-9, you may download the Form w9 pdf  and send it to them or have them download it and send it back to you. The business owner/employer who requests the form does not have to submit it to the IRS unless the IRS requests it. However, you should keep all completed Form W-9s on file in case that request comes.
How to Fill Out a W-9
- Download the 2013 W9 form from the IRS . Check the appropriate box for your classification. Individuals serving as independent contractors should check individual/sole proprietor.
- Check the box if you are an exempt payee (exempt from backup withholding )
- Fill out your address
- Fill out your Tax ID number. For individuals this is your Social Security number. For businesses it is your Employer Identification Number. For trusts or estates it could be a different number provided by the IRS.
- Read the certification and sign the Form W-9.
- Submit the Form W-9 to the person or business that requested it.