Employer National Insurance Calculator (UK)
Use this calculator to estimate standard Class 1 secondary (employer) National Insurance for one pay run and for a full year.
How employer National Insurance is calculated
Employer National Insurance (often called secondary Class 1 NICs) is the amount an employer pays on an employee’s earnings above a set threshold. In simple terms, the calculation is:
Employer NI = (Gross Earnings − Secondary Threshold) × Employer NI Rate
If earnings are below the threshold, the employer NI for that pay period is usually zero.
The key inputs you need
- Gross pay for the pay period (before tax and deductions).
- Pay frequency (weekly, monthly, annual).
- Tax year settings (rate + threshold can change by year).
- Number of employees at that pay level.
- Employment Allowance remaining (if your business qualifies).
Example calculation
Let’s say you are in tax year 2025/26, paying one employee monthly £3,000 gross, with a monthly secondary threshold of £416.67 and employer NI rate of 15%.
- NICable pay = £3,000 − £416.67 = £2,583.33
- Employer NI = £2,583.33 × 15% = £387.50 (approx.)
If you had 5 employees at the same pay level, your estimated monthly employer NI would be around £1,937.50.
Typical thresholds and rates by tax year (illustrative)
| Tax Year | Employer NI Rate | Annual Secondary Threshold | Monthly Threshold | Weekly Threshold |
|---|---|---|---|---|
| 2024/25 | 13.8% | £9,100 | £758.33 | £175.00 |
| 2025/26 | 15.0% | £5,000 | £416.67 | £96.15 |
Employment Allowance and why it matters
Employment Allowance can reduce your annual employer NI bill, sometimes by a substantial amount. If your business is eligible, the allowance is offset against your employer NIC liability over the year until used up.
In practice, that means:
- Your gross employer NI is calculated as normal each period.
- Your remaining allowance is applied against the annual liability.
- You pay only the net amount once allowance is considered.
Common mistakes in employer NI calculations
1) Using the wrong tax year
Rates and thresholds can change between years, so a stale spreadsheet can quickly become inaccurate.
2) Mixing annual and monthly thresholds
If payroll is monthly, use monthly thresholds. If payroll is weekly, use weekly thresholds.
3) Forgetting reliefs or special categories
Some employees may attract different treatment, and certain reliefs can reduce your liability. This calculator estimates the standard employer NI scenario.
4) Ignoring Employment Allowance eligibility rules
Not every employer can claim it. Confirm eligibility before relying on allowance-adjusted totals.
Step-by-step workflow for payroll teams
- Choose the tax year and confirm current HMRC settings.
- Set the payroll frequency (weekly or monthly).
- Calculate gross pay for each employee.
- Apply threshold and employer NI rate.
- Total all employees for the pay run.
- Apply Employment Allowance balance if eligible.
- Reconcile against payroll reports before submission.
Frequently asked questions
Is employer NI the same as employee NI?
No. Employee NI is deducted from the employee’s wages. Employer NI is an additional cost paid by the employer.
Can I use this for forecasting staff costs?
Yes. It is useful for budgeting and scenario planning, especially when comparing salary bands and hiring plans.
Does this include every edge case?
No. It models standard secondary Class 1 NIC. Complex cases should be validated in professional payroll tools.
Final thoughts
A clear employer national insurance calculation process helps prevent underpayments, overpayments, and end-of-year surprises. With the calculator above, you can quickly estimate period and annual employer NI costs, then layer in Employment Allowance to see your likely net liability.