Hi,
I currently live and work in NJ and am considering taking a job in Rockland County, NY. I know how to fill in a W4 but what I really want to know is what will be the tax difference if I take the job in NY state?

Thanks in advance.

If you take this job in Rockland County you will have to pay NY State income tax on your wages there. You will also have to continue to pay NJ income tax, but NJ lets you take a credit for taxes you paid to NY. Since NY's tax rates are higher than NJ's, you will most likely not owe NJ any tax at all (unless you have other sources on NJ income, such as dividends, capital gains, or a spouse who works in NJ). Bottom line is that you will end up paying more tax on the same salary by taking the NY job than if you eared the same wage in NJ. It's impossible to say how much more since you didn't provide any details, but for comparison the NY tax rate is 6.85% on income between $20K and $100K, and 7.375% on income over that. This compares with NJ's rate of 5.525% on income between $40K and $75K, and 6.37% on income from $75K to $500K.

Also, do NOT forget the commuting costs.

With gas prices hovering at $4 per gallon, that is NOT an insignificant cost!