First of all thank you for your reply on my last post about tax filing for 2 states. I have one more question. As per your reply I have to file taxes for 2 states now. But I have a W 2 from one state only. I am a consultant working in IA while my employer is in NJ. The withheld taxes are paid to NJ and my employer gave me a w 2 for that state only. How can I file as there is no IA state w 2. And my employer's state is NJ, so what about his state employer id number for IA ?

No money was withheld for the state of Iowa, which is why there is no Iowa W-2.

However, you must still file an Iowa return. Just attach the W-2 you have. You may get hit with an underwithholding penalty, but not if you attach a letter to the return explaining what happened.

You will get all the NJ withheld tax back, which will offset what you owe to Iowa.