If you have two or more jobs, Class 1 National Insurance is normally worked out separately on each job, with its own thresholds, so you can pay less than someone earning the same total from one job. The exceptions are jobs with the same employer, or with employers carrying on business in association, where earnings must usually be added together, and there is an annual maximum that caps what you pay overall.

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How is National Insurance worked out when you have two jobs?

Paragraph 1 of Schedule 1 to the Social Security Contributions and Benefits Act 1992 sets the starting point, as summarised in HMRC’s National Insurance Manual at NIM10001:

  • all earnings from one employment are added together;
  • earnings from more than one employment with the same employer must be added together unless regulations say otherwise;
  • earnings from employments with different employers are not added together unless regulations say otherwise.

So in the ordinary case of two unrelated employers, each payroll applies the full set of thresholds to the pay it makes. For 2026 to 2027 GOV.UK gives these weekly figures, which apply job by job:

Threshold (2026 to 2027) Weekly What happens
Lower earnings limit £129 Earnings at this level protect your National Insurance record
Primary threshold £242 Employee pays 8% above this, up to the upper earnings limit
Upper earnings limit £967 Employee pays 2% above this
Secondary threshold £96 Employer pays 15% above this

The thresholds are not shared between jobs. Each employer applies the primary threshold and the secondary threshold in full, which is why two part time jobs can attract less National Insurance in total than one full time job paying the same.

Illustration: two small jobs compared with one

Illustration only. Sam earns £230 a week from each of two jobs in 2026 to 2027.

  • Two unrelated employers. Each job is below the £242 primary threshold, so Sam pays no employee National Insurance. Each employer pays 15% on £134 (£230 less £96), so £20.10 each, £40.20 a week in total.
  • Both jobs with one employer, aggregated. Earnings of £460 are treated as one payment. Sam pays 8% on £218 (£460 less £242), which is £17.44 a week. The employer pays 15% on £364, which is £54.60 a week.

The difference is large enough that HMRC looks closely at arrangements where pay is split across roles or companies.

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When must earnings from the same employer be added together?

As a rule, always. Regulation 14 of the Social Security (Contributions) Regulations 2001 gives only a narrow exception: earnings from employments with the same employer need not be aggregated if they are separately calculated and, as a result, it would not be reasonably practicable to aggregate them (NIM10002).

HMRC’s view at NIM10009 is that the burden is on the employer, that the decision is not once and for all, and that having a computerised payroll which cannot aggregate is not by itself enough. HMRC weighs the cost of aggregating against the loss of contributions and of the employee’s benefit and pension entitlement, and expects manual fixes to be considered and costed. Where earnings are aggregated, GOV.UK’s employer guidance says the total is calculated on one payroll record, the other record shows nil year to date National Insurance, and the aggregated earnings indicator is set in the Full Payment Submission. Any student loan deduction is also worked out on the aggregated figure.

When are jobs with different employers added together?

Regulation 15 of the 2001 Regulations requires aggregation across different employers in three situations, unless it is not reasonably practicable (NIM10003 to NIM10006):

  1. the employers are carrying on business in association with each other (regulation 15(1)(a));
  2. one of the employers is treated as the secondary contributor for each employment under Schedule 3 to the Social Security (Categorisation of Earners) Regulations 1978 (regulation 15(1)(b));
  3. some other person is treated as the secondary contributor for each employment under that Schedule (regulation 15(1)(c)).

“Business in association” is not defined in law. HMRC’s guidance at NIM10010 reads it as combining for a common purpose, supported by sharing things such as premises, staff, equipment, customers, profits or losses. Common directors or a shared office are not enough on their own if there are no financial links; two companies that jointly run one project and share its costs and profits would usually be in association. GOV.UK notes this can apply where there is a holding company or shared ownership.

Where associated employers aggregate, regulation 15(2) says the employer contributions on the combined earnings are shared in proportions they agree or, failing agreement, in proportion to the earnings each pays.

Is there a cap on what you pay across all your jobs?

Yes. Regulation 21 of the 2001 Regulations sets an individual annual maximum for people with more than one employment in the tax year (NIM37010). There is no annual limit on employer contributions. NIM01251 sets out the calculation for 2024 to 2025 onwards:

  1. take the upper earnings limit less the primary threshold and multiply by 53;
  2. multiply that by 8%;
  3. add together your earnings between the primary threshold and the upper earnings limit in every job;
  4. deduct the step 1 figure from the step 3 total and, if the result is positive, multiply it by 2%;
  5. add 2% of all your earnings above the upper earnings limit in every job;
  6. the maximum is the total of steps 2, 4 and 5.

In effect, only one band’s worth of earnings is charged at the main rate, and everything else is charged at 2%. If you have paid more than this, the excess can be refunded. NIM37003 says there is no time limit for claiming back contributions paid above the annual maximum, though HMRC will not refund very small sums (NIM37002). Our guide to National Insurance refunds explains how to claim.

Can you avoid overpaying during the year?

If one job pays at or above the upper earnings limit all year, you can apply to defer contributions on the others. GOV.UK says that for 2026 to 2027 you need to earn £967 or more a week in one job and £242 or more a week in the second (or £1,209 or more a week from two jobs and £242 or more in the others if you have more than two). The deferred job then deducts 2% instead of 8% on earnings between £242 and £967, and HMRC checks the position after the year ends. The process, deadlines and year end check are covered in our guide to deferring Class 1 National Insurance.

What about your State Pension record?

Because the thresholds apply to each job, low earnings in several jobs are not combined to reach the lower earnings limit unless the aggregation rules apply. GOV.UK says that an employee earning from £129 to £242 a week from one job usually pays nothing but has contributions treated as paid to protect their record. Someone with several jobs each paying under £129 a week may get no qualifying year from any of them, even though the total is well above the limit. In that situation it is worth checking your National Insurance record and whether voluntary contributions would fill the gap.

What if you are employed and self employed?

Class 1 on the job and Class 4 on the profits are charged separately, with the annual maximum rules limiting the combined bill. GOV.UK says HMRC tells you what is due after your Self Assessment return is filed, and you cannot defer Class 4. See employed and self employed at the same time and our guide to self employed National Insurance.

Common mistakes

  • Splitting one role into two contracts with the same employer. Earnings must still be added together unless the narrow regulation 14 exception genuinely applies.
  • Assuming group companies are always in association, or never are. HMRC looks at the actual relationship, not just shareholdings (NIM10010).
  • Not claiming an excess refund. High earners with two jobs often pay above the annual maximum without realising it.
  • Ignoring the State Pension effect. Several very small jobs can leave gaps in the record.

Current thresholds for every class are collected in our 2026 to 2027 rates and thresholds page.

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Reviewed by Christine Anderson, Broker, Solar Protect. Last reviewed 8 October 2026. Part of Accountapedia, the Solar Protect guide to UK tax and accounting. This page is general information, not personalised advice.