I have a itin number but i also have social security that i work with. how can does it work

Assuming you are using a fake SSN to work, you would need to enter the ITIN in the personal section but the SSN on the W2. If you are using Turbotax, you cannot efile that return. You will need to print and mail it in with the copy of the W@, so the IRS can match the W2 to your ITIN. Generally, the IRS does allow efiling with an ITIN/SSN mismatch, but Turbotax doesnt support that. There might be other software out there that does.

Edited.  2/10/2016 12:26 AM

Did you mean by you also have a social security number issued from the Social Security Administration?   Usually an ITIN is applied when there is no social security number available or you are waiting for the social security number after apply.  If you have both numbers and they are issued by the government , I will suggest you to use the social security number.  

Does TurboTax still not let you efile? Do you know of any other software that does let you? Thanks.

When you file, you file using your ITIN number.  Then when you enter the W2 you edit the social security number to reflect the number on your w2 and any other info.  You may end up having to mail in the return.  The IRS allows this.  https://www.irs.gov/individuals/international-taxpayers/individual-taxpayer-identification-number-itin-reminders-for-tax-professionals

• Tax returns filed with an Individual Taxpayer Identification Number reporting wages paid are required to show the Social Security Number under which the wages were earned.  This creates an identification number (ITIN/SSN) mismatch.  In the past, returns with this mismatch could only be filed on paper.  Due to programming changes the IRS' e-file system can now accept these returns.  The taxpayer's correct ITIN should be used as the identifying number at the top of Form 1040.  When inputting W-2 information, the SSN should be entered exactly as shown on the Form W-2 issued by the employer.  It is now possible to e-file a return with an ITIN/SSN mismatch.