N.J. Stat. § 54:5-75: Installments unpaid; municipality to proceed for balance only

If an installment is not paid when due, or redemption is not completed within the time fixed in the resolution, the municipality, in any subsequent proceedings to enforce or foreclose the tax sale lien, or sell, assign, transfer or alienate it, shall proceed only for the unpaid balance after proper credit of such installment payments as were made.