Income Tax vs. NI 2026: The True Cost of Salary

In the UK, your "headline" tax rate (e.g., 20% or 40%) rarely tells the full story. To understand your true take-home pay, you must look at the combined impact of Income Tax and National Insurance (NI).

1. The 2026 Landscape

As of the 2026/27 tax year, the thresholds for Income Tax and NI have been largely aligned. Both typically start at £12,570 (the Personal Allowance and Primary Threshold).

Income Tax Bands

• Personal Allowance: £0 - £12,570 (0%)
• Basic Rate: £12,571 - £50,270 (20%)
• Higher Rate: £50,271 - £125,140 (40%)
• Additional Rate: Over £125,140 (45%)

National Insurance (Class 1)

• Primary Threshold: £12,570 (0%)
• Main Rate: £12,571 - £50,270 (8%)
• Upper Rate: Over £50,270 (2%)

2. The "Combined" Marginal Rate

When you earn an extra pound, you aren't just paying one tax. You are paying both. Here is the combined reality for most employees in 2026:

• Earnings £12,571 - £50,270: 20% (Tax) + 8% (NI) = 28% Combined
• Earnings £50,271 - £100,000: 40% (Tax) + 2% (NI) = 42% Combined
• Earnings £100,001 - £125,140: 60% (Tax) + 2% (NI) = 62% Combined
• Earnings Over £125,140: 45% (Tax) + 2% (NI) = 47% Combined

3. Why NI is Often Called a "Stealth Tax"

While Income Tax is widely understood, National Insurance is often overlooked. However, for a basic rate taxpayer earning £30,000, NI accounts for a significant portion of the total deductions.

Crucially, NI does not have the same reliefs as Income Tax. For example, while pension contributions (via Net Pay) reduce your Income Tax, they only reduce your NI if your employer uses a Salary Sacrifice arrangement.

4. Key Takeaways for 2026

1. Threshold Alignment: The alignment of the NI Primary Threshold with the Personal Allowance has simplified the system but frozen thresholds mean "fiscal drag" continues to pull more people into higher brackets.
2. Salary Sacrifice is King: If your employer offers Salary Sacrifice for pensions or electric cars, take it. It is the only way to save on both Income Tax and National Insurance simultaneously.
3. Check Your Code: Ensure your tax code (usually 1257L) is correct. An incorrect code affects your Income Tax but not your NI.

---

Understand your deductions in detail with our National Insurance Calculator.