*****Disclaimer: This is not legal advice and is for educational purposes only. This does not create an attorney-client privilege.
A W-9 form is a Request for Taxpayer Identification Number and Certification form from the Internal Revenues Board (IRS) that allows an individual or business to send their tax payer identification number to others. It is a very straight-forward and simple information form, only a page long. You can find a copy of a W-9 form that is ready to be filled out here https://www.irs.gov/pub/irs-pdf/fw9.pdf.
The W-9 form is a document that you would never have reason to send to the IRS itself. It is most commonly sent to someone so that they can send you back Form 1099, another IRS form which is needed for tax purposes in cases where someone paid you greater than $600. This form can allow your taxpayer identification number to be sent to individuals, clients, businesses, banks and other financial institutions.
This form is very straightforward, as its only purpose is to formally send only the information necessary to paying your taxes. You can send either your social security number or your employer identification number.
Essentially this form is useful in scenarios where someone or some entity is responsible for filing the information return regarding yourself to the IRS. This form can be used in variety of cases including; income paid to you, contributions you made to an IRA, real estate transactions, mortgage interest you paid, cancellation of debt, or an acquisition or abandonment of secured property.
Some of the more specific, common situations wherein you would need this form include the following. One common reason would be that banks sometimes ask for them when opening a new account. Another reason could be that a bank or financial institution you are investing with might need it in order to submit other 1099 form types necessary to account for interest income, proceeds from real estate transactions, etc. Another very common reason would be if you are hired as an independent contractor and will be paid more than $600 by a given client in one year. Once submitted you can file the 1099-MISC form you will need to report for taxes.
Some of the other necessary entries on the form include your full legal name, as shown on your federal tax income returns. You then select your tax classification from a list of options that includes the most common choice of Individual/sole proprietor or single-member LLC, C Corporation, S Corporation, Partnership, Trust/estate, or a Limited Liability company. You will also include your address, and finally your signature and the date. It is very straight-forward!