Starting 6 April 2025, employers begin paying NI on an employee’s wages once those earnings hit £96 a week (that’s £417 a month or £5,000 a year). Because the threshold is dropping, some part-timers who used to fly under the radar will now cost their bosses NI. To make life tougher, the employer rate itself jumps from 13.8 % to 15 %. There is a sweetener: the Employment Allowance doubles to £10,500 and, for the first time, larger businesses can claim it (one-person companies where the sole worker is also the director still can’t). Smaller firms may even see their overall NI bill shrink thanks to that bigger allowance, but big employers should brace for a hefty hit. All the existing higher NI-free limits for under-21s, apprentices, veterans and those hired in Freeports or Investment Zones stay put, so recruiting in those categories still cuts costs. Class 1A and Class 1B rates, which cover benefits and PAYE settlement agreements, rise in step with the main employer rate to 15 %.

Employees get off lightly. Nothing changes to the point where your own NI kicks in: you still start paying at £242 a week (£1,048 a month or £12,570 a year) at a rate of 8 %, then drop to 2 % once earnings top £967 a week (£4,189 a month or £50,270 a year). If you earn between the lower earnings limit of £125 a week and that £242 threshold, you’re treated as though you’ve paid NI—even though you haven’t—so you still chalk up a qualifying year for the state pension.

For the self-employed, Class 4 NI stays as is: 6 % on profits between £12,570 and £50,270 and 2 % above that. The small-profits threshold nudges up to £6,845; if your profits land between that figure and the £12,570 lower profits limit, you get a credit to protect your pension record. Earn less than £6,845 and you can still choose to pay voluntary Class 2 contributions at £3.50 a week to keep that record going.

Finally, anyone who needs to plug gaps in their contribution history but can’t pay Class 2 can opt for voluntary Class 3 contributions, which will cost £17.75 a week for 2025/26.

In short, employers—especially the bigger ones—feel most of the squeeze, employees see no real change, and the self-employed only need to note a few small tweaks.