NI for Multiple Jobs

Key facts

NI is calculated independently for each job — each employer applies the Primary Threshold separately.
You could pay more NI across two jobs than someone earning the same total from one job.
You can apply to defer Class 1 NI at one employer if you are likely to overpay.
If you overpay NI, you can claim a refund after the end of the tax year.

NI With Multiple Employments

If you work for more than one employer, each employer calculates your National Insurance independently. Unlike Income Tax — where your total income is considered across all sources — NI is blind to your other employments.^[1]

This can lead to you paying more NI overall than if you earned the same total amount from a single employer.

How NI Is Calculated Per Job

Each employer:^[2]

Applies the Primary Threshold to your earnings from their employment only
Charges 8% on earnings between PT and UEL
Charges 2% on earnings above UEL
Has no visibility of your other employment

Example — two jobs, each paying £25,000/year:

Job 1: 8% on £12,430 (£12,570 to £25,000) = £994.40
Job 2: 8% on £12,430 (£12,570 to £25,000) = £994.40
Total NI: £1,988.80

Compare — one job paying £50,000/year:

8% on £37,700 (£12,570 to £50,270) = £3,016.00
Total NI: £3,016.00

In this case, the single-job worker actually pays more because the 8% band is wider. But the scenario reverses when total earnings are much higher and the 2% rate above UEL is involved.

When Overpayment Occurs

Overpayment is most likely when:^[1]

Your total earnings across all jobs are well above the Upper Earnings Limit (£50,270/year)
At least one job pays you above the UEL for that employment alone
You end up paying 8% at one job on earnings that should be at 2% when your total income is considered

Overpayment example:

Job 1: £40,000/year — NI: 8% on £27,430 = £2,194.40
Job 2: £30,000/year — NI: 8% on £17,430 = £1,394.40
Total NI paid: £3,588.80
NI if earned £70,000 from one job: 8% on £37,700 + 2% on £19,730 = £3,016 + £394.60 = £3,410.60
Overpayment: £178.20

Applying for NI Deferment

If you expect to overpay NI because of multiple employments, you can apply to HMRC to defer Class 1 contributions at one of your jobs:^[3]

Complete form CA72A (Application for Deferment)
Submit it to HMRC, ideally before the start of the tax year
If approved, one employer will deduct NI at the reduced 2% rate instead of 8%
At the end of the year, HMRC calculates the correct NI and you pay any balance or receive a refund

Tip: Apply for deferment at the job with the lower earnings. That way, the higher-earning job continues to collect NI normally (giving you the full benefit of the thresholds), and the lower-earning job collects at the reduced 2% rate.

Claiming a Refund

If you did not apply for deferment and you have overpaid NI, you can claim a refund after the end of the tax year:^[1]

Write to HMRC National Insurance Contributions Office, or call 0300 200 3500
Provide your NI number, employer details, and earnings from each job
HMRC may also identify overpayments automatically and issue refunds
Refunds can sometimes take several months to process

Employer NI Across Multiple Jobs

Each employer pays their own employer NI independently. There is no annual maximum for employer NI — each employer pays 15% on earnings above the Secondary Threshold (£5,000/year) for their employment only. Employer NI cannot be deferred or refunded in the same way as employee NI.

NI vs Tax: Multiple Jobs

Feature	Income Tax	National Insurance
Calculated across all jobs?	Yes (cumulative, one tax code split across employers)	No (per employment)
Overpayment risk?	Lower (tax code adjustments prevent most overpayment)	Higher (no cross-employer visibility)
Refund process	Usually automatic via tax code	Manual claim or automatic HMRC review

Practical Tips for Multiple Job Holders

Check your P60s at the end of the year — add up your total NI to see if you may have overpaid
Apply for deferment if your combined earnings are likely to exceed £50,270
Keep records of all employment earnings for refund claims
Contact HMRC early if your employment situation changes mid-year

Frequently Asked Questions

Why do I pay more NI with two jobs than one?

Because NI is calculated per employment. Each employer applies the full Primary Threshold (£242/week) to your earnings from that job alone. If you earn £25,000 from each of two jobs, each employer calculates NI on £25,000 independently — you lose the benefit of the 2% rate above the UEL that you would get in a single £50,000 job.

Can I defer NI payments if I have two jobs?

Yes. If your total earnings from multiple employments exceed the Upper Earnings Limit (£50,270 per year), you can apply to HMRC using form CA72A to defer Class 1 NI at one of your employers. HMRC will calculate the correct NI at the end of the year and adjust accordingly.

How do I claim a refund for overpaid NI?

If you did not defer and you overpaid NI, you can claim a refund after the end of the tax year by writing to HMRC or by calling the National Insurance helpline on 0300 200 3500. HMRC may also identify overpayments automatically and issue a refund.

Does having two jobs affect my State Pension?

Having two jobs does not give you extra qualifying years. You only need one qualifying year per tax year for State Pension purposes. As long as at least one of your employments gives you earnings above the Lower Earnings Limit, you are building your pension record.

Sources

National Insurance if you have more than one job — GOV.UK
National Insurance rates and categories — GOV.UK
Defer your National Insurance — GOV.UK