Monthly Employer NI Calculator 2026/27
Employer NI calculator
Add each pay level in your team. Get the bill, the cost and the working.
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Estimate only. Independent tool, not affiliated with HMRC. Rates checked 20 October 2026. Real payroll rounds each pay period.
Most UK payrolls run monthly, so employer NI is worked out one month at a time. In 2026/27 you pay 15% on each employee’s monthly pay above £417. On monthly pay of £2,500, that is £312.45. The calculator above is set to monthly pay.
In this guide13 sections
The monthly method
HMRC payroll software uses a monthly Secondary Threshold of £417. This is the £5,000 yearly threshold divided by 12 and rounded.
Monthly employer NI = (monthly pay − £417) × 15%
For £2,500 of pay: £2,500 − £417 = £2,083. Then £2,083 × 15% = £312.45.
Monthly examples
| Monthly pay | Above £417 | Employer NI for the month | Over a year |
|---|---|---|---|
| £1,500 | £1,083 | £162.45 | £1,949.40 |
| £2,500 | £2,083 | £312.45 | £3,749.40 |
| £3,500 | £3,083 | £462.45 | £5,549.40 |
| £5,000 | £4,583 | £687.45 | £8,249.40 |
Over a full year these come out a few pence below the yearly method. For £30,000 a year, the yearly sum gives £3,750, while twelve monthly sums give £3,749.40. HMRC allows this small rounding difference.
More monthly figures
| Monthly pay | Employer NI | Cost to employ for the month |
|---|---|---|
| £1,000 | £87.45 | £1,087.45 |
| £2,000 | £237.45 | £2,237.45 |
| £3,000 | £387.45 | £3,387.45 |
| £4,000 | £537.45 | £4,537.45 |
| £6,000 | £837.45 | £6,837.45 |
| £8,000 | £1,137.45 | £9,137.45 |
Pay of £417 or less in a month brings no employer NI at all. Part-time staff on small wages may cost you only their pay.
When one month costs more
A bonus, back pay or an overtime spike raises that month’s employer NI. The extra pay is charged at the full 15%, because the month’s threshold is already used up. A £2,000 bonus adds £300. Our guide to employer NI on bonuses shows how to plan for it.
Directors are different. They use an annual earnings period, so a monthly bill can swing sharply. See the director NI calculator.
A full monthly payroll run
A small firm runs payroll for six staff. Here is what its employer NI looks like in one ordinary month.
| Employee | Monthly pay | Employer NI |
|---|---|---|
| Manager | £4,200 | £567.45 |
| Senior assistant | £2,600 | £327.45 |
| Assistant | £2,100 | £252.45 |
| Assistant | £2,100 | £252.45 |
| Part-time assistant | £900 | £72.45 |
| Apprentice (under 25, approved) | £1,600 | £0 |
The month’s bill is £1,472.25 before Employment Allowance. The apprentice costs nothing in employer NI because the 0% rate applies up to £4,189 a month. See apprentice employer NI.
Monthly, four-weekly and weekly thresholds
| Pay period | Secondary Threshold | Upper threshold (under 21, apprentice, veteran) |
|---|---|---|
| Weekly | £96 | £967 |
| Every 4 weeks | £385 | £3,867 |
| Monthly | £417 | £4,189 |
| Yearly | £5,000 | £50,270 |
The full list is on the employer NI thresholds page.
Four-weekly and weekly employers use the same method with a different threshold. A weekly wage of £620 gives (£620 − £96) × 15% = £78.60. A four-weekly wage of £2,300 gives (£2,300 − £385) × 15% = £287.25.
Step by step: check your payroll run
- Take the employee’s gross pay for the month. Include overtime, bonuses and commission.
- Take off £417. If the answer is zero or less, no employer NI is due for that employee.
- Multiply what is left by 15%.
- Add the figures for all employees to get the month’s employer NI.
- Take off any Employment Allowance your payroll software applies. It is used up month by month until the £10,500 is gone.
Payroll software does steps 1 to 5 for you. Use the calculator to check the answer before you approve a run.
Starters, leavers and part months
When someone joins or leaves part-way through a month, you pay them for the days they worked. The threshold stays at £417 for that pay period, so a short month can fall below it.
| Situation | Pay for the month (about) | Employer NI |
|---|---|---|
| Joins halfway, £2,500 salary | £1,250 | £124.95 |
| Leaves after one week, £2,500 salary | £577 | £24 |
| Joins on the last day, £2,500 salary | £81 | £0 |
Leavers paid for unused holiday get that pay in their final period, so their last month can be higher. See NI on statutory and termination pay for other one-off payments.
How Employment Allowance shows up month by month
Employment Allowance is not taken off each employee. It is a credit against your total bill. A firm with a monthly employer NI bill of £900 would owe nothing until the £10,500 allowance runs out. That takes about 11 to 12 months, so the allowance covers most of the year.
If your monthly bill is £2,000, the allowance lasts a little over five months. After that, you pay the full £2,000 each month. Cash planning is easier if you know which month the allowance runs out.
| Month | Bill | Allowance used | You pay | Allowance left |
|---|---|---|---|---|
| April | £2,000 | £2,000 | £0 | £8,500 |
| May | £2,000 | £2,000 | £0 | £6,500 |
| June | £2,000 | £2,000 | £0 | £4,500 |
| July | £2,000 | £2,000 | £0 | £2,500 |
| August | £2,000 | £2,000 | £0 | £500 |
| September | £2,000 | £500 | £1,500 | £0 |
| October onwards | £2,000 | £0 | £2,000 | £0 |
See the Employment Allowance guide for who can claim.
Mistakes to avoid
- Using £416.67 or £5,000 for a monthly run. Payroll uses £417.
- Forgetting that bonuses are charged in the month paid. A big December bonus lifts December’s bill.
- Treating directors like other staff. Directors use an annual method. Their monthly NI can look different from the table above.
- Applying the 0% rate to an employee who just turned 21. The lower rate stops when they turn 21, so update the category letter. See the under-21 guide.
- Forgetting a pay rise. A rise from October lifts every later month. Re-run the calculator from that month.
Frequently asked questions
How do I work out employer NI each month?
Take the employee’s monthly pay, subtract £417, and multiply what’s left by 15%. If the pay is below £417, no employer NI is due that month.
How much is employer NI on £3,000 a month?
£387.45. That is £3,000 minus £417, which is £2,583, multiplied by 15%. Over twelve months the bill is £4,649.40.
Is the monthly threshold £417 or £416.67?
HMRC publishes £417 for payroll. The exact yearly threshold divided by 12 is £416.67, so figures from different tools can differ by a few pence.
Do I pay employer NI monthly to HMRC?
Yes, as part of your PAYE bill, normally by the 22nd of the following month. See how to pay employer NI.
How much is employer NI on £2,000 a month?
£237.45. That is £2,000 minus £417, which is £1,583, multiplied by 15%.
Is employer NI on a month with a bonus higher?
Yes. The bonus is added to that month’s pay and charged at 15% in full. Your threshold for the month is already used up by the normal salary.
When does Employment Allowance run out?
It runs out when your employer NI bills since April reach £10,500. A business with a £1,500 monthly bill uses it up in seven months.
What do I do if the calculator and my software differ by a few pence?
Trust your payroll software. It follows HMRC’s rounding rules. Use the calculator for planning and budgets.
What is the monthly employer NI on £1,000 of pay?
£87.45. That is £1,000 minus £417, multiplied by 15%.
Is the monthly bill the same as the yearly bill divided by 12?
Not exactly. Payroll uses a rounded £417 monthly threshold, so twelve monthly sums come out a little different from the yearly sum divided by 12. The gap is under £1 for a standard employee.
Related guides
- Employer National Insurance Calculator 2026/27
- Employer NI Thresholds 2026/27: Weekly, Monthly, Yearly
- How Employer National Insurance Is Calculated
- Employer NI on Bonuses (2026/27)
Official sources
- National Insurance rates and categories
- HMRC: Rates and thresholds for employers 2026 to 2027
This page is independent information, not tax advice, and has no link with HMRC. Figures were checked on 20 October 2026 for the 2026/27 tax year. Always confirm the final figures with HMRC or your payroll provider.