Penalty and interest will be charged for both late filing of a tax return and late payment of tax due as follows:
The late filing penalty is 5% of the tax due for each month or portion of a month the return is late. The maximum penalty for late filing is 25%. The Division may also charge a penalty of $100 for each month the return is late.
A late payment penalty of 5% of the tax due may also be charged.
Interest is calculated at the annual rate of 3% above the prime rate for every month or portion of a month the tax is unpaid, compounded annually. At the end of each calendar year any tax, penalties and interest still due become part of the balance on which interest is charged.
Please visit the NJ dept of Taxation :
http://www.state.nj.us/treasury/taxa...s/tb/tb21t.pdf