Problem with setting up taxes for NJ state only

[schobook]

In zone definitions I have the following
Zone Name##########_Zone Description##########Status
New Jersey##########_Tax for NJ##############Green

I have this for the details of the zone definition
Country ###############Zone
United States ##########_New Jersey

Here are my tax rates.
Priority##########_Tax Class ##########Zone ##########Tax Rate ##########Description:
0 ##############Taxable Goods########New Jersey######7%##############NJ Tax Rate

I have done a few tests and yes NJ residents get charged 7% tax but so do other states.

My question is how do I make it so that I only charge NJ residents tax and no other states?

I have seen the Local Sales Tax Mod but I don't want to use any mod on my site other than the USPS one because they can cause errors. There should be a way without this mod. Does anyone know? If you need more information I can provide it.

Thank you.