I lived the whole year in NJ.
I worked roughly 50% time in NY and 50% time in NJ for the same employer.
I received a single W2 where in #16: NY wages are 100% of all wages (state requirement), and NJ wages are the part I earned in NJ, like 50%. Now when I try to fill NJ tax return info online it asks me to delete wages. But as far as I understood I should include all my wages to NJ return. If I exclude NY wages I would only report NJ part.. If I leave both I would report 150% of my income..
What should I do?
Exclude the NJ wages. Because of reporting and programming requirements for NJ, your employer must report both of these lines, and then TurboTax adds them both together to determine the taxable amount. Since 100% of the wages are reported to NY already, you do not want to have extra "phantom" income included on your NJ return. NJ does tax all of your income, including income that NY is also taxing, but you will get a credit on your NJ return for the tax you must pay to NY.
It is for this reason you must make sure you prepare the NY return first. The fact that your employer must report all of your income to NY is curious but explainable. There are two possibilities. The first is that you are a telecommuter. If you are, NY taxes all of your income. The other possibility is that, as a NY nonresident, you physically worked in a NJ location for your company that is not your home. If that is the case, then you need to make sure that you fill out the allocation screen in the NY return to determine the correct method of adjusting your NY nonresident income to reflect the amounts that you earned within New York State. For instructions to help you to fill out this form (if you need them), here's a link to IT-203-B Nonresident and Part-Year Resident Income Allocation and College Tuition Itemized Deduction Worksheet
But the NY allocation does not affect the entry on the NJ return. Here is a screenshot of that key screen, but in your case select the NJ box instead of the NY box so that 100% of your wages are correctly reported to NJ:
Exclude the NJ wages. Because of reporting and programming requirements for NJ, your employer must report both of these lines, and then TurboTax adds them both together to determine the taxable amount. Since 100% of the wages are reported to NY already, you do not want to have extra "phantom" income included on your NJ return. NJ does tax all of your income, including income that NY is also taxing, but you will get a credit on your NJ return for the tax you must pay to NY.
It is for this reason you must make sure you prepare the NY return first. The fact that your employer must report all of your income to NY is curious but explainable. There are two possibilities. The first is that you are a telecommuter. If you are, NY taxes all of your income. The other possibility is that, as a NY nonresident, you physically worked in a NJ location for your company that is not your home. If that is the case, then you need to make sure that you fill out the allocation screen in the NY return to determine the correct method of adjusting your NY nonresident income to reflect the amounts that you earned within New York State. For instructions to help you to fill out this form (if you need them), here's a link to IT-203-B Nonresident and Part-Year Resident Income Allocation and College Tuition Itemized Deduction Worksheet
But the NY allocation does not affect the entry on the NJ return. Here is a screenshot of that key screen, but in your case select the NJ box instead of the NY box so that 100% of your wages are correctly reported to NJ: