If you are self-employed in the UK, National Insurance for the self-employed is something you cannot really sidestep. It shows up on your Self Assessment tax return each year, and how much you pay depends on how profitable your work has been. Yet it is one of those topics that tends to get a brief mention and then glossed over, which means a lot of sole traders and freelancers reach their first tax bill with only a vague sense of what they are paying or why.

There are two classes of National Insurance relevant to self-employed people: Class 2 and Class 4. They work differently, they are calculated differently, and they protect different things. Once you understand the distinction, the whole picture becomes a good deal clearer.

Below we explain both classes, the current rates for 2026/27, the thresholds that matter, and one recent change worth being aware of if you have worked outside the UK.

Self-employed National Insurance splits into two separate classes, and the two are often confused because they appear together on the same tax return.

Class 2

Class 2 is a flat weekly contribution. For 2026/27 the rate is £3.65 per week. If your profits reach or exceed £7,105 for the year, HMRC treats Class 2 as having been paid automatically through your Self Assessment return. You do not need to do anything separately. If your profits sit below that level, you are not required to pay, though you can make voluntary contributions if you want to protect your record.

Class 4

Class 4 is a percentage-based contribution calculated on your profits, and it is the one that tends to produce the larger number. For 2026/27 you pay 6% on profits between £12,570 and £50,270, and 2% on any profits above £50,270. There is nothing to pay on profits below the lower threshold of £12,570, which aligns with the personal allowance.

Both classes are paid through your annual Self Assessment tax return. Class 4 is calculated automatically once you have entered your profit figures, so there is no separate form to file.

It helps to run through a couple of examples to see how these figures land in real terms.

Example 1: profits of £30,000

On £30,000 of self-employed profit in 2026/27, your Class 4 liability would be 6% on the amount between £12,570 and £30,000. That is 6% of £17,430, which comes to £1,045.80. Class 2 is treated as paid because profits are above the £7,105 annual threshold.

Example 2: profits of £60,000

On £60,000 of profit, you pay 6% on the band between £12,570 and £50,270 (£37,700), giving £2,262. You then pay 2% on the amount above £50,270, which is £9,730, adding another £194.60. Total Class 4: roughly £2,456.60. Again, Class 2 is treated as paid.

These figures sit on top of income tax, which is why it is worth knowing them in advance rather than absorbing the surprise come January. The combined income tax and National Insurance bill is what your Self Assessment payment on account will be based on, so the earlier you have a clear picture of your profit, the better placed you are to set money aside.

One thing that surprises a lot of self-employed people is that National Insurance contributions are not just a tax in the pure sense. They build your National Insurance record, which determines your entitlement to certain state benefits.

The main ones relevant to self-employed people are:

• State Pension: you generally need 35 qualifying years of contributions for a full new State Pension. Class 2 contributions count towards this.
• Employment and Support Allowance (contributory): again, Class 2 contributions can count towards eligibility, depending on your record.
• Maternity Allowance: self-employed women can qualify based on their Class 2 record rather than employment earnings.

This is why the voluntary Class 2 option matters if your profits are below the £7,105 annual threshold. Paying voluntarily at £3.65 a week (roughly £190 a year) buys you a qualifying year on your record. For someone with gaps in their history, that can be well worth it, particularly in the years leading up to State Pension age. If you are uncertain about your current record, you can check it through your personal tax account on HMRC’s website.

From 6 April 2026, HMRC removed access to voluntary Class 2 National Insurance contributions for periods spent working abroad, for most self-employed individuals. Previously, self-employed people working outside the UK could choose to continue paying Class 2 contributions voluntarily to protect their UK National Insurance record. That option is no longer available to most people for the 2026/27 tax year onwards.

The only exceptions are self-employed individuals who are treated as gainfully self-employed in the UK under a relevant international social security agreement, and volunteer development workers paying the specific VDW rate.

If you were already making voluntary Class 2 contributions as an overseas worker, HMRC will write to you (from July 2026 onwards) about the closure of your Class 2 liability and what you can do instead. There is a transitional window: existing Class 2 customers can apply to pay Class 3 contributions without meeting the usual new 10-year residency or qualifying-years criteria, provided they apply before 6 April 2027.

If this affects your situation, it is worth acting before that deadline rather than leaving it until your next Self Assessment filing. Class 3 contributions protect the State Pension record in the same way, but the rate is higher than Class 2, so the sooner you understand your position the better.

If your self-employed profits are modest, the thresholds work slightly differently and it is worth knowing where they sit.

For 2026/27 there are effectively three levels that matter for Class 2:

• Below £6,725 (small profits threshold): no Class 2 is due and none is treated as paid. You can pay voluntarily if you wish to protect your record.
• Between £6,725 and £7,105: no Class 2 payment is required, but your contributions are treated as paid for record purposes. This effectively gives you a qualifying year at no cost.
• £7,105 and above (annual threshold): Class 2 is treated as paid automatically through your Self Assessment return.

For Class 4, the calculation only starts above the £12,570 lower profits limit, so if your profits are below that level no Class 4 is due either.

This is relevant for people who are self-employed part-time, or in the early months of a new business before income has built up. It does not mean you can skip registering with HMRC. You still need to register for Self Assessment if you are self-employed, even if you end up owing very little. How to register as self-employed with HMRC covers that process if you are still at that stage.