Class 4 NIC Annual Maximum Calculator 2025/26
Calculate if you have overpaid NIC when you have both employment and self-employment income. Class 4 NIC annual maximum limits total NIC — claim your refund via Self Assessment.
Class 4 NIC Annual Maximum Calculator 2025/26
If you have both employed and self-employed income, you may have paid too much NIC overall. Calculate your refund entitlement.
Frequently Asked Questions
What is the Class 4 NIC annual maximum?
The annual maximum limits how much National Insurance a person with both employed and self-employed income needs to pay in a tax year. If your combined Class 1 (employment) and Class 4 (self-employment) NIC exceeds what you would have paid if all your earnings were from employment, you can claim a refund of the excess.
Who does this affect?
The annual maximum affects people who: (1) have more than one employment, (2) have both employment and self-employment income, or (3) have multiple self-employed businesses. It is most common for doctors, lawyers, or consultants who work both as employees and run their own practice.
What are the Class 4 NIC rates for 2025/26?
Class 4 NIC rates for 2025/26: 6% on profits between £12,570 and £50,270 (Lower and Upper Profits Limits), and 2% on profits above £50,270. Note these rates were reduced from 9%/2% to 6%/2% from 6 April 2024 and remain at these rates for 2025/26.
How do I claim a Class 4 NIC refund?
HMRC automatically applies the annual maximum calculation when processing your Self Assessment tax return and will adjust your Class 4 NIC liability. If you have overpaid, the refund appears in your SA calculation. Alternatively, complete the annual maximum calculation in your SA return.
Is Class 2 NIC still a consideration?
Class 2 NIC was abolished from 6 April 2024 for most self-employed people. Those with profits above the Small Profits Threshold (£6,725) now get Class 2 NIC entitlement (for state pension purposes) automatically without making a separate payment. Class 2 only needs to be paid voluntarily if profits are below £6,725 to maintain state pension entitlement.
What is the actual HMRC annual maximum formula?
HMRC uses the formula in NIM24055: essentially, the maximum employee NIC payable if all combined earnings were employment income, less Class 1 already paid, with the remainder being the maximum Class 4 payable. The calculation involves the equivalent Class 1 liability on all earnings.
Can I avoid overpaying by applying in advance?
HMRC allows deferment of Class 4 NIC (form CA72A) if you know in advance you will exceed the annual maximum. This prevents overpayment during the year rather than claiming a refund after the year end.
Does the annual maximum apply to employer NIC?
No — the annual maximum only applies to employee Class 1 NIC and Class 4 NIC. Employer NIC (Class 1 secondary) is charged on each employment separately with no annual maximum cap.