CBT-160-A: Underpayment of Estimated Corporation Business Tax on Gross Receipts of less than $50,000,000 (2025)
New Jersey · NJ Division of Taxation · Used for tax years 2025
Form CBT-160-A helps corporations with total gross receipts of less than $50 million determine whether they paid enough estimated New Jersey Corporation Business Tax for 2025. It calculates underpayments, checks exceptions to interest charges, and figures any installment interest
Who files this form
Form CBT-160-A is for corporations, including separate and combined filers, with total gross receipts of less than $50 million. It determines whether estimated tax payments were sufficient and whether interest is due on an underpayment.
Submit the form with your CBT-100, CBT-100S, or CBT-100U if you use it to calculate underpayment interest or to show that you qualify for an exception.
When it's due
For the 2025 tax year, enter estimated-tax installment dates corresponding to the 15th day of the fourth, sixth, ninth, and 12th months of your tax year.
Interest runs from the installment due date to the payment date or the 15th day of the fifth month after the close of the 2025 tax year, whichever is earlier. This is the interest calculation cutoff, not a separately stated filing deadline.
Submit CBT-160-A with your tax return. The text does not give a separate filing deadline for this form.
What you'll need
Have these returns and records available:
- Your 2025 CBT-100, CBT-100S, or CBT-100U. Line 1 uses page 1, line 6 of CBT-100, line 4 of CBT-100S, or line 5 of CBT-100U.
- Your 2024 return. Line 3 uses page 1, line 6 of CBT-100, line 4 of CBT-100S, or line 5 of CBT-100U.
- Records of estimated-tax payments and credits, including amounts and payment dates.
- Your name as shown on the return, federal ID number, and unitary ID number, if applicable.
- If claiming an exception, the prior-year return information or tax information for the months used in the annualized-tax calculation.
How to file
- Complete Part I, lines 1 through 9, to check for an underpayment in each installment period.
- If line 9 shows an underpayment, complete Part II to see whether either exception applies.
- If neither exception applies for a payment period, complete Part III, lines 13 through 18, to calculate interest.
- Enter the total interest from line 18 on page 1, line 12 of CBT-100 or CBT-100S, or page 1, line 14 of CBT-100U.
- Submit CBT-160-A with your CBT-100, CBT-100S, or CBT-100U when calculating interest or claiming an exception.
Banking and financial corporations are subject to electronic filing requirements for all tax filings and payments for privilege periods ending on and after July 31, 2023. The text directs them to the Division of Taxation’s website for more information.
The text does not provide a mailing address or detailed electronic filing steps.
Common mistakes
- Carrying forward too much overpayment: Line 7b allows only the overpayment on line 9 that exceeds the total of all earlier underpayments.
- Leaving out separate calculations: If the corporation made more than one payment for an installment, include a separate computation for that installment.
- Ignoring partial months: A part of a month counts as a full month when calculating interest.
- Ignoring rate changes: Changes in the average predominant prime rate must be reflected in the interest calculation. The Division publishes interest rates on its website.
- Using a short prior-year return without annualizing it: For Exception I, divide taxable net income by the number of whole months covered by the short-period return, then multiply by 12.
Questions people ask
Does an underpayment on line 9 automatically mean I owe interest?
No. Complete Part II to check the exceptions. You do not owe interest for a payment period if your payments on line 10 were made on time and equal or exceed either applicable amount calculated on lines 11 and 12.
What are the two exceptions?
Exception I uses the facts on the prior-year return and the law applicable to that year, but applies current-year rates. Exception II uses annualized tax for months preceding an installment date.
What if I qualified and elected to make a single payment instead of installments?
The form directs you to enter zero on line 2 if you qualified and elected to make a single payment instead of estimated-tax installments.
How is underpayment interest calculated?
Interest is calculated on the underpayment from the installment due date to the payment date or the 15th day of the fifth month after the tax year closes, whichever is earlier. The annual rate is 3% above the average predominant prime rate, and interest applies for each month or part of a month the underpayment exists.