Answers · UK 2025/26

How does National Insurance work if I have two jobs?

Unlike Income Tax, National Insurance is generally calculated separately for each job, meaning you get the National Insurance Primary Threshold applied in each employment individually, which can mean you pay less combined National Insurance across two modest jobs than you would on the same total income from a single job.

Last updated: 3 July 2026Last reviewed: 3 July 2026How we verify

Full answer

National Insurance for employees with more than one job works quite differently from Income Tax, and understanding this difference can matter financially. For Class 1 employee National Insurance, each employer generally calculates and deducts National Insurance independently, applying the £12,570 Primary Threshold separately to each individual employment, rather than considering your combined earnings across all jobs the way Income Tax effectively does over the course of a tax year. This means someone earning, for example, £10,000 from one job and £10,000 from a second job (£20,000 combined) could in some circumstances pay no employee National Insurance at all on either job individually, since neither individually exceeds the £12,570 Primary Threshold, even though their combined income of £20,000 would clearly exceed that threshold if it all came from a single employer. This is a genuine, legitimate quirk of how the system is structured, rather than an error, though HMRC does have a mechanism (via a 'deferment' or, more commonly today, an automatic annual reconciliation process) to review combined National Insurance liability across multiple jobs and correct any significant under- or over-payment where thresholds interact in unusual ways, particularly for higher earners who might otherwise avoid the 2% additional rate that should apply above the combined Upper Earnings Limit. Someone with several part-time jobs whose combined earnings are substantial, or who is close to National Insurance thresholds across multiple employments, can apply to HMRC to defer National Insurance in one job to avoid overpaying, though for most people with modest earnings across a couple of part-time roles, the separate-threshold treatment is simply a modest, legitimate advantage of the system as it stands.