My colleague is in the following situation:

They moved from NJ to FL in July 2008 when they purchased a home. They did not have any property or any residence whatsoever any longer in NJ at that point.

They began working for an employer in Florida in September 2008. My colleague left the company prior to actually seeing a pay statement and found out in February when the W-2 was sent that the employer took out NJ tax. Not sure how this happened as no form he filled out (including application and resume) had his former NJ address, however, they apparently still still kept his NJ address from an old resume they had of him from careerbuilder. When he got an offer in August, they sent the offer to his former NJ residence and he told them he doesn't live in NJ anymore and to fix the address and they said OK and resent it to the FL address.

So fast forward to February 2009 and his W2 shows income reported to NJ and state tax taken out. The employer says they can not do anything about it as it was already filed and they could not reimburse him. Since his W2 for this employer has NJ State income reported along with the state tax taken from his paycheck, what does he need to do to get fix this when he files 2008 taxes. What form does he need to fill out to adjust and take off this income in his State return as being earned as a resident of NJ and get the tax back?

He is using H&R Tax Cut to file his Federal and NJ Part Year Resident State Taxes

Timeline:

Jan 1 - Jun 30 2008 - Colleague was full time resident of NJ
Jul 1 - Present Colleague was full time resident of NJ
9/08 - Colleague started working at employer in FL (employer had old NJ address in payroll apparently and taxed colleague as if he lived in NJ still.)

If you are present in a state, then any income earned during this period, must be reported to the state.
To your resident state, you must report your worldwide income for the year or for the residency period. If you paid taxes to another state, then you will claim credit for those taxes.

Read: Your U.S. Tax Return: Working or Living in Two or More states (http://taxipay.blogspot.com/2008/06/working-in-two-or-more-states.html)

This is the issue: My colleague was living in FL when he earned the wages from the FL employer.

The employer should not have taken NJ State Tax out. That was incorrect on their part.

So how does he go about getting that money back.

FL has no state individual income tax so there is nothing on Florida's side to file.

On his part year resident NJ State tax forms, his wages are incorrectly stated and higher than they should be, along with the tax already withheld, and the tax liability.

How to amend this?

It CAN be amended, but the process is too complicated to explain on a forum such as this.

He should get professional tax help to fix he problem.