What is National Insurance?
A separate tax on earnings that also builds your entitlement to the State Pension.
National Insurance sits alongside Income Tax rather than inside it, and it buys you something: qualifying years towards the State Pension and some other benefits. Self-employed people meet it as Class 4 and Class 2.
Class 4 for 2026/27 is 6% on profit between £12,570 and £50,270, then 2% on anything above. It comes out through your Self Assessment return, not separately.
Class 2 is the one people get wrong. It was not abolished; it stopped being compulsory. At £7,105 of profit or more it is treated as paid, so you get the pension record without a bill. Below that you owe nothing, but you can pay it voluntarily at £3.65 a week to stop a gap appearing in your record.
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