Class 4: the main charge on profits
Class 4 National Insurance applies to your self-employed profits, worked out on your Self Assessment return alongside Income Tax. GOV.UK's current rates are:
- 6% on profits between £12,570 and £50,270
- 2% on profits above £50,270
Class 2: now largely automatic
Class 2 still exists, but GOV.UK confirms that for people with profits above a small-profits threshold (£7,105), Class 2 contributions are treated as having been paid to protect your National Insurance record — you don't need to pay it separately. Below that threshold, you can choose to pay Class 2 voluntarily, currently £3.65 a week, to keep your record building towards the State Pension and other benefits.
How it's collected
GOV.UK is clear that most self-employed people pay both Class 2 and Class 4 through Self Assessment, calculated and included in the same bill as your Income Tax, due by the same 31 January deadline.
Why the voluntary Class 2 payment can be worth it
If your profits are low enough that Class 2 isn't automatically treated as paid, a small voluntary payment can still be worth making, since gaps in your National Insurance record can affect your entitlement to the State Pension and certain benefits later on.
Getting your bill right
National Insurance is easy to overlook when estimating what you'll owe, since it's calculated separately from Income Tax but paid on the same date. We work out both classes correctly as part of preparing your return.
Need a hand with your return?
We prepare and file Self Assessment returns for directors, sole traders and landlords, and tell you exactly what is due and when before anything is submitted. Call 0114 327 1480.