A £1,500 pension sacrifice on a £30,000 salary saves approximately £420 in income tax and NI in 2026/27. The net cost to your take-home pay is £90/month.
With a £30,000 gross salary, a £1,500 pension sacrifice reduces your taxable salary to £28,500. You pay income tax and National Insurance on the lower figure, not the original £30,000.
At £30,000, your salary sits within the basic-rate (20%) income tax band. Each £1,000 sacrificed saves £200 in income tax, plus £80 in employee NI (at the 8% rate below £50,270) — a combined saving of £280 per £1,000 sacrificed.
The £1,500 goes into your pension. You receive the full £1,500 pension contribution, but your take-home pay only falls by £1,080 per year (£90/month) — the difference is the tax and NI you no longer pay.