Do I pay National Insurance on my side hustle if I have a job?

Usually not. Class 4 National Insurance is worked out on your self-employed profit on its own, and only starts once that profit is over £12,570. Your wages have Class 1 taken off through PAYE as normal, but they do not count towards the Class 4 threshold.

What are the Class 4 National Insurance rates for 2026–27?

6% on self-employed profits between £12,570 and £50,270, and 2% on profits above £50,270. There is nothing to pay on profits of £12,570 or less.

Do I still have to pay Class 2 National Insurance?

No. If your profits are £7,105 or more in 2026–27 you are treated as having paid it, and the year counts towards your State Pension. Below that you can choose to pay voluntarily, at £3.65 a week.

Is voluntary Class 2 worth paying?

It can be if the year would not otherwise count towards your State Pension. At £3.65 a week it is much cheaper than voluntary Class 3 at £18.40 a week. Check your National Insurance record first, because a job may already give you a qualifying year.

Hamster blog

Do you pay National Insurance on side hustle income?

By the Hamster team · Published 25 October 2026

Last checked: 25 October 2026 against GOV.UK · Figures are for the 2026–27 tax year unless stated

The short answer

Only if your self-employed profit is over £12,570 in 2026–27. Class 4 National Insurance is 6% of profit between £12,570 and £50,270 and 2% above that, worked out on your side hustle profit alone, not added to your salary. Class 2 is no longer compulsory: profit of £7,105 or more counts towards your State Pension automatically, and below that you can choose to pay £3.65 a week.

Two kinds of National Insurance for the self-employed

When you are employed, Class 1 National Insurance comes off your wages through PAYE. In 2026–27 employees pay 8% on earnings above £242 a week, up to the upper earnings limit, and 2% above it.

Side hustle income is self-employed income, and that has its own two classes:

Class 4, a percentage of your profit, paid through Self Assessment
Class 2, a flat weekly amount that is now voluntary for most people

Class 4: on your profit alone

Class 4 for 2026–27:

nothing on profits up to £12,570
6% on profits between £12,570 and £50,270
2% on profits above £50,270

The important word is profit: your side hustle income minus your allowable expenses or the £1,000 trading allowance. And Class 4 looks at your self-employed profit on its own. Your salary does not count towards the £12,570, which is why most people with a job and a modest side hustle pay Income Tax on it but no National Insurance.

Profit, not takings, is what matters. A delivery rider who takes £15,000 in a year but claims £4,000 in mileage and other costs has £11,000 of profit, which is under £12,570, so pays no Class 4 at all.

That is different from Income Tax, where your profit is added on top of your salary. See PAYE job plus side hustle for how that works.

Class 4 is paid with your Income Tax through Self Assessment, and it is included in payments on account if you make them.

Class 2: voluntary, and cheap

Class 2 used to be a compulsory weekly charge. It no longer is. For 2026–27:

If your profits are £7,105 or more, you are treated as having paid Class 2. You pay nothing, and the year counts towards your State Pension.
If your profits are below £7,105, you do not have to pay anything, but you can choose to pay voluntary Class 2 at £3.65 a week, which is £189.80 for a full year.

Voluntary Class 2 is the cheapest way to fill a year on your National Insurance record. The alternative, voluntary Class 3, is £18.40 a week in 2026–27.

It only helps if the year would not already count. If you have a job, your Class 1 contributions may already give you a qualifying year, so check your National Insurance record before paying. You must be registered as self-employed for Class 2 to be treated as paid or to pay it voluntarily.

Worked examples

A job plus a small side hustle. Hannah earns £30,000 as a teaching assistant and makes £4,000 profit from tutoring. Her profit is under £12,570, so Class 4 is £0. Her job's Class 1 is unchanged.

A full-time side hustle. Ravi has no job and makes £20,000 profit as a self-employed electrician's mate.

Class 4: (£20,000 − £12,570) × 6% = £445.80
He is over £7,105, so Class 2 is treated as paid and the year counts towards his State Pension.

A bigger profit. Leila makes £60,000 profit from her photography business.

6% on £12,570 to £50,270: £37,700 × 6% = £2,262
2% on £50,270 to £60,000: £9,730 × 2% = £194.60
Class 4: £2,456.60

A small profit and no job. Tom left work to care for a relative and makes £5,000 profit selling furniture he restores. Class 4 is £0. His profit is under £7,105, so the year will not count towards his State Pension unless something else covers it, such as National Insurance credits. He can choose to pay voluntary Class 2: £189.80 for the year.

Your 2025–26 return

The return due on 31 January 2027 uses the 2025–26 figures. The Class 4 thresholds and rates were the same, but the Class 2 small profits threshold was £6,845 and the voluntary rate was £3.50 a week.

To pay voluntary Class 2 for 2025–26, put an X in box 36 of the SA103S pages. The notes say you cannot pay it voluntarily through Self Assessment after 31 January 2027.

Who does not pay Class 4

The 2025–26 notes say you are exempt from Class 4 if you had reached State Pension age on or before 6 April 2025, were under 16 on that date, or were not resident in the UK for tax purposes during the year. If one of those applies, there is a box to tick (box 37).

Keeping track

The question is whether your profit, on its own, will pass £12,570 or £7,105 by 5 April. Hamster is a free Android app that works out your Class 4 National Insurance alongside your Income Tax as you log earnings and costs, keeping your salary out of the National Insurance sum and in the Income Tax one.

Quick answers

Do I pay National Insurance on my side hustle if I have a job?: Usually not. Class 4 National Insurance is worked out on your self-employed profit on its own, and only starts once that profit is over £12,570. Your wages have Class 1 taken off through PAYE as normal, but they do not count towards the Class 4 threshold.
What are the Class 4 National Insurance rates for 2026–27?: 6% on self-employed profits between £12,570 and £50,270, and 2% on profits above £50,270. There is nothing to pay on profits of £12,570 or less.
Do I still have to pay Class 2 National Insurance?: No. If your profits are £7,105 or more in 2026–27 you are treated as having paid it, and the year counts towards your State Pension. Below that you can choose to pay voluntarily, at £3.65 a week.
Is voluntary Class 2 worth paying?: It can be if the year would not otherwise count towards your State Pension. At £3.65 a week it is much cheaper than voluntary Class 3 at £18.40 a week. Check your National Insurance record first, because a job may already give you a qualifying year.

Sources

How we check our numbers

This is general information, not personal tax advice. Rules and rates change — check the linked GOV.UK pages or speak to an accountant about your own situation.