The April 2025 NLW and NI changes: what it actually costs your business

Two changes landed on April 1 2025 that most SME owners underestimated at the time. The National Living Wage increased from £11.44 to £12.21 per hour — a 6.7% rise. Simultaneously, the employer National Insurance secondary threshold dropped from £9,100 to £5,000 per year, and the rate increased from 13.8% to 15%. Understanding the combined cost is not optional. It is the difference between trading profitably and funding a wage increase that destroys your margin.

The numbers per employee

For a full-time employee on minimum wage (37.5 hours/week): the wage increase alone adds £1,306.50 per year. Employer NI on the wage increase at 15% adds approximately £196. The expanded NI base (lower threshold) adds approximately £615 per employee in additional employer NI even before the wage increase is factored in.

Total additional cost per full-time minimum wage employee: approximately £1,900–2,100 per year depending on your specific pay structure. For a business with 10 minimum-wage staff, that is £19,000–21,000 of additional annual cost — appearing from nowhere on 1 April 2025.

The differential compression nobody talks about

Your employees on minimum wage got a pay rise. Your employees earning £14–16 per hour — the ones with three years of experience and institutional knowledge — did not. Their advantage over a new starter has compressed from £4.56 per hour to £2.79. That is the gap between experienced and inexperienced staff. In tight labour markets, experienced staff notice this compression. Some leave. Replacing them costs 20–40% of their annual salary in recruitment and training. The wage compression problem often costs more than the minimum wage increase itself.

Three responses that work

Price review: If labour is 35% of your cost base and it rises by 7%, that is a 2.5% overall cost increase. A 3% price increase covers it. Most buyers in 2025/26 accept labour-driven price increases if communicated clearly and in advance.

Utilisation and scheduling: Are you using your paid hours efficiently? An employee paying £12.21/hour who is actively productive for 5.5 of 8 hours costs £17.76 per productive hour. Improving utilisation from 69% to 80% reduces the effective cost per productive hour to £15.26 without touching the wage.

Employment Allowance: This increased to £10,500 from April 2025. If you have not applied for the increase through HMRC, do it now. For small businesses with a modest employer NI bill, this single action may recover a significant portion of the increased cost.