National Insurance for Self-Employed: What You're Paying For (In Plain English)
Quick Answer
National Insurance (NI) is a tax that funds the State Pension and some benefits. As a self-employed person, you typically pay two types: a small flat-rate Class 2 and a percentage-based Class 4 on your profits. Combined with Income Tax, NI is part of your total tax bill.
Target Searches
- national insurance self employed uk
- how much NI do I pay self employed
- class 2 vs class 4 ni
- what is national insurance for
- self employed national insurance calculator
- ni contributions sole trader
- do I pay NI if self employed
- national insurance and state pension
- ni thresholds self employed
- self employed tax and ni
What is National Insurance?
National Insurance is a tax that everyone working in the UK pays (in some form). It's separate from Income Tax but collected alongside it.
Your NI contributions go towards:
- State Pension – Your NI record affects how much State Pension you receive
- Maternity Allowance – For self-employed mothers
- Some other benefits – Bereavement, Jobseeker's Allowance (contribution-based)
It's not a savings pot with your name on it—it's a tax that funds current benefits while building your entitlement record.
The Two Types of NI for Self-Employed
Class 2 National Insurance
A flat weekly amount that self-employed people pay.
- Collected through your Self Assessment bill (not weekly in practice)
- You only pay if your profits are above the Small Profits Threshold
- Relatively small amount per year
Class 2 helps you build up "qualifying years" for your State Pension.
Class 4 National Insurance
A percentage of your profits above a threshold.
- This is the bigger one for most self-employed people
- Calculated on profits between the Lower Profits Limit and Upper Profits Limit
- Higher rate above the Upper Profits Limit (but a lower percentage)
How NI is Generally Calculated
NI rates and thresholds change. Here's how it generally works (check HMRC for current figures):
Class 2:
- Fixed weekly rate × 52 weeks
- Only if profits are above the Small Profits Threshold
Class 4:
- A percentage (historically around 6–9%) on profits between the Lower Profits Limit and Upper Profits Limit
- A smaller percentage (historically around 2%) on profits above the Upper Profits Limit
Example (illustrative only):
If your profit is £35,000, and:
- Lower Profits Limit is £12,570
- Upper Profits Limit is £50,270
- Class 4 rate is 6% / 2%
Class 4 NI = (£35,000 − £12,570) × 6% = £22,430 × 0.06 = £1,345.80
Plus a small Class 2 amount.
Always check current rates on HMRC's website.
Worked Example
Emma is a freelance illustrator.
- Annual profit: £42,000
Estimated NI calculation:
- Class 4 on profits £12,570–£42,000 = £29,430 × 6% = £1,765.80
- Class 2 (e.g., ~£180/year) = £180
- Total NI: ~£1,946
This is on top of her Income Tax. To estimate your full bill (Income Tax + NI), use our calculator.
What You Get in Return
State Pension
Your NI record determines:
- Whether you qualify for the full State Pension
- How much you'll receive
You need around 35 qualifying years of NI contributions for the full amount. Each year you pay enough NI counts as a qualifying year.
Tip: Check your NI record on the HMRC website to see how many qualifying years you have.
Maternity Allowance
Self-employed mothers can claim Maternity Allowance based on their NI record. You don't get Statutory Maternity Pay (that's for employees), but Maternity Allowance is an alternative.
Some Contribution-Based Benefits
- Bereavement benefits
- Contribution-based Jobseeker's Allowance
- Contribution-based Employment and Support Allowance
These depend on your NI record, not means testing.
NI vs Income Tax: What's the Difference?
| Income Tax | National Insurance | |
|---|---|---|
| What it funds | General government spending | Pensions & specific benefits |
| Personal Allowance | Yes (e.g., £12,570 tax-free) | Different thresholds apply |
| Rate structure | 20% / 40% / 45% bands | Flat (Class 2) + percentage (Class 4) |
| Affects your pension? | No | Yes – NI builds qualifying years |
Both are calculated on your profit, but with different rules.
Do You Have to Pay NI?
If your profits are above the threshold
Yes. Class 4 NI is mandatory if profits exceed the Lower Profits Limit.
If your profits are below the threshold
You may not have to pay, but you can choose to pay voluntary Class 2 contributions to protect your State Pension record.
If you're also employed
You might pay NI twice:
- Class 1 NI through your employer (deducted from salary)
- Class 2 + Class 4 on your self-employed profits
There's a maximum annual limit, so if you overpay, you can claim a refund.
Common Mistakes
1. Forgetting NI exists
Many people only think about Income Tax and are surprised when NI adds to the bill.
2. Not checking your NI record
Gaps in your record can affect your State Pension. Check on HMRC's website.
3. Confusing Class 2 and Class 4
Class 2 is a small fixed amount. Class 4 is percentage-based and usually the bigger one.
4. Not understanding thresholds
If your profit is below the Lower Profits Limit, you don't pay Class 4. But you might want to pay voluntary Class 2.
5. Ignoring voluntary contributions
If you have a low-profit year, voluntary contributions can be worth it to maintain your pension record.
FAQ
Do I pay NI on turnover or profit?
Profit. Just like Income Tax.
What's the difference between Class 2 and Class 4?
Class 2 is a small flat amount. Class 4 is a percentage of your profits.
How do I pay NI?
It's included in your Self Assessment tax bill. You don't pay it separately.
What if I'm employed and self-employed?
You may pay NI on both. There's an annual maximum to prevent excessive double-payment.
Does NI reduce my Income Tax?
No. They're separate calculations on the same profit.
What happens if I don't pay NI?
You'll owe it anyway (HMRC will chase), and your State Pension record may have gaps.
Can I check my NI record?
Yes. Log into your Personal Tax Account on GOV.UK to see your record.
Is Class 2 being abolished?
There have been proposals, but check current HMRC guidance. As of now, it's still in place.
Do I need 35 years of NI for full State Pension?
Yes—35 qualifying years for the full new State Pension.
What's a qualifying year?
A year where you've paid or been credited with enough NI contributions.
Next Steps
Now you understand what NI is, make sure you're setting aside enough to cover it alongside Income Tax.
Learn about profit vs turnover and allowable expenses to reduce your taxable profit.
Back to the Learn hub.
This guide is for general information only. Tax rules change, and everyone's situation is different. Always check the latest HMRC guidance and consider speaking to a qualified accountant if you're unsure.