Employer duties by number of employees: the UK thresholds
Most of UK employment law applies from the first person you hire. A short list of duties switches on later, at 5, 10, 20, 21, 50 and 250. This page puts them in order, with the source for each number.
Most employer duties in the UK start with the first employee: employers' liability insurance, a written statement of terms, a workplace pension, a health and safety policy and a right to work check. Six more are tied to size. At 5 employees the health and safety policy and risk assessment must be written down. At 10 on one premises you must keep an accident record. Proposing 20 redundancies triggers collective consultation. Above 21 a union can apply for statutory recognition. At 50 employees can request an information and consultation agreement, and at 250 you must publish your gender pay gap.
Which duties start at which size?
Each row is the point at which a duty begins. Nothing in an earlier row falls away as you grow.
| Size | What starts | Where it comes from |
|---|---|---|
| 1 | Employers' liability insurance of at least £5 million; written statement of terms on or before day one; automatic enrolment duties; a health and safety policy and risk assessment (need not be written yet); a recorded fire risk assessment; a right to work check; disciplinary and grievance rules in writing; privacy information | Employers' Liability (Compulsory Insurance) Act 1969; Employment Rights Act 1996, ss.1-3; Pensions Act 2008; Health and Safety at Work etc. Act 1974 |
| 5 | The health and safety policy must be written down; the significant findings of the risk assessment, and your arrangements, must be recorded | HSWA 1974, s.2(3) and the 1975 Exception Regulations; Management of Health and Safety at Work Regulations 1999, regs 3 and 5 |
| 10 | An accident record for the premises, kept for at least three years | Social Security (Claims and Payments) Regulations 1979, reg 25 |
| 20 | Collective consultation, and notice to the Redundancy Payments Service on form HR1, if you propose 20 or more redundancies within 90 days at one establishment | Trade Union and Labour Relations (Consolidation) Act 1992, s.188; gov.uk |
| 21 | A union you have declined to recognise can apply to the Central Arbitration Committee for statutory recognition | TULRCA 1992, Schedule A1; gov.uk |
| 50 | Employees can formally request an information and consultation agreement; in a TUPE transfer you can no longer consult staff directly unless fewer than 10 are transferring | Information and Consultation of Employees Regulations 2004; TUPE Regulations 2006 |
| 250 | Gender pay gap reporting, every year | Equality Act 2010 (Gender Pay Gap Information) Regulations 2017 |
Two cautions on counting. Each rule has its own definition of who counts - employees, workers, people on one premises, people at one establishment - so check the definition before relying on being one short. And the count is usually taken on a particular date, not as an average.
What applies from the first employee?
Almost everything. The idea that small firms are exempt from employment law is the most expensive misunderstanding in this subject. From the day your first member of staff starts you need:
- Employers' liability insurance covering at least £5 million, from an authorised insurer. gov.uk says you can be fined £2,500 for every day you are not properly insured, and £1,000 for not displaying the certificate or refusing to make it available to inspectors.
- A written statement of employment particulars for every employee and worker, given on or before their first day. The template lists what it must contain.
- A workplace pension. The Pensions Regulator says: "Your automatic enrolment duties start when you employ your first member of staff." You must write to staff within six weeks of that date and complete a declaration of compliance within five months. The auto-enrolment guide has the detail.
- A health and safety policy and a risk assessment. Both duties exist at one employee. Only the requirement to write them down waits until five.
- A fire risk assessment, recorded in full. In England and Wales this has applied to every responsible person, whatever the headcount, since 1 October 2023.
- A right to work check before employment begins, with a dated copy kept for the length of employment and two years after. Use the checklist.
- Disciplinary rules and a grievance route in writing. There is no small-employer exemption; see the policies the law requires.
Holiday, the minimum wage, statutory sick pay, family leave, protection from discrimination and the right to request flexible working are likewise owed by every employer, of any size.
What changes at 5 employees?
Three things must now be on paper: the health and safety policy, the significant findings of your risk assessment, and the arrangements you have made to manage health and safety. The duties themselves are not new at five; the record is. HSE's wording on the policy is: "If you have five or more employees, you must write your policy down."
The health and safety policy template is written for this moment, and the health and safety handbook covers the rest.
What changes at 10 employees?
Where ten or more people are normally employed at the same time on the same premises, the employer must keep a record of accidents and hold each entry for at least three years. It can be a book or an electronic record. The rule sits in social security law, not health and safety law, which is why it is so often missed.
Below ten you still have to report certain injuries under RIDDOR and keep those records, so most small employers keep an accident record from the start.
What happens at 20 and 21?
Twenty is a count of redundancies, not of staff. gov.uk states: "You must follow 'collective consultation' rules if you're making 20 or more employees redundant within any 90-day period at a single establishment." Consultation must start at least 30 days before the first dismissal takes effect for 20 to 99 redundancies and at least 45 days before for 100 or more, and the Redundancy Payments Service must be notified on form HR1 within the same periods. An employer with fewer than 20 employees can never reach it; one with 25 can. The redundancy process guide covers individual consultation, which applies at every size.
Twenty-one is the union recognition line. gov.uk tells employers: "If you do not want to recognise the union and have more than 21 employees, they can apply for statutory recognition from the Central Arbitration Committee". Below that size recognition can only be voluntary.
What changes at 50 employees?
- Information and consultation. Employees of an organisation with at least 50 employees can request a formal agreement on being informed and consulted. Acas says that for businesses with fewer than 750 employees at least 15 people must make the request, and at 750 or more it is at least 2% of employees. You are not required to set one up unprompted.
- TUPE. For transfers completing on or after 1 July 2024, gov.uk says employers can inform and consult directly with their employees if they either have fewer than 50 employees or are transferring fewer than 10 employees. At 50 and above, with 10 or more transferring, you must go through representatives.
What changes at 250 employees?
Gender pay gap reporting. gov.uk: "Any employer with 250 or more employees on a specific date each year (the 'snapshot date') must report their gender pay gap data." The snapshot date is 5 April for private and voluntary sector employers and 31 March for most public authorities, and the figures must be reported and published within a year of it.
Three other things attach to the same number:
- Action plans. Since 6 April 2026, employers with 250 or more employees "have the option to produce and publish a voluntary action plan alongside their gender pay gap data", covering the gender pay gap and support for employees going through the menopause. gov.uk says that, subject to legislation, these will become mandatory from spring 2027.
- Ethnicity and disability pay gap reporting is proposed for employers of 250 or more. It is not law, and no start date has been set.
- Data protection records. The partial exemption from keeping a record of processing activities applies only below 250 people, and even then not to regular HR processing. See the employee privacy notice template.
Which thresholds are about money, not headcount?
Several duties people expect to be about headcount are set by turnover or by a mixed test.
- Modern slavery statement: annual turnover of £36 million or more.
- Off-payroll working (IR35): you must decide your contractors' tax status once you are no longer a small company. On gov.uk's current guidance that means meeting two or more of: turnover above £10.2 million, a balance sheet total above £5.1 million, more than 50 employees. The money thresholds rise to £15 million and £7.5 million for financial years beginning on or after 6 April 2025.
- Data protection fee: £52 a year with no more than 10 staff or turnover up to £632,000; £78 with no more than 250 staff or turnover up to £36 million; £3,763 above that.
The supplier register template covers the contractor and supply chain duties.
How do you stay ahead of the next threshold?
- Know your number on the right definition. Employees, workers and people on site are three different counts.
- Act one hire early. Write the health and safety policy at four; start the accident record at nine. Neither costs anything to do sooner.
- Put the dated rules in the calendar. The gender pay gap snapshot and the pension re-enrolment date recur whether or not anyone remembers.
- Keep the evidence where the next person can find it. A duty met but not recorded is hard to prove after the manager who met it has left.
Frequently asked questions
Are small businesses exempt from employment law in the UK?
No. Almost all UK employment law applies from the first employee, including employers' liability insurance, the written statement of terms, automatic pension enrolment, minimum wage, holiday and protection from discrimination. Only a short list of duties depends on size.
At how many employees do you need a written health and safety policy?
Five. Every employer must have a health and safety policy, but it only has to be written down when there are five or more employees. The significant findings of the risk assessment must be recorded from the same point.
At how many employees do you need an accident book?
An accident record is required where ten or more people are normally employed at the same time on the same premises, under the Social Security (Claims and Payments) Regulations 1979. Entries must be kept for at least three years.
How many employees before you need a pension scheme?
One. The Pensions Regulator says automatic enrolment duties start when you employ your first member of staff. You must write to staff within six weeks and complete a declaration of compliance within five months.
How many employees before gender pay gap reporting applies?
250. Any employer with 250 or more employees on the snapshot date, which is 5 April for private and voluntary sector employers, must report and publish its gender pay gap within a year of that date.
When does collective redundancy consultation apply?
When an employer proposes to make 20 or more employees redundant within any 90-day period at a single establishment. Consultation must start at least 30 days before the first dismissal, or 45 days where 100 or more are affected.
Sources
Checked against the primary source on 5 October 2026.
- gov.uk: employers' liability insurance - the £5 million minimum and the fines
- The Pensions Regulator: new employers - duties start date, six weeks and five months
- HSE: prepare a health and safety policy - written down at five or more employees
- Social Security (Claims and Payments) Regulations 1979, reg 25 - the accident record at ten or more
- gov.uk: redundancy consultations - 20 or more redundancies, 30 and 45 days, form HR1
- gov.uk: employers recognising a trade union - the statutory recognition threshold
- Acas: requesting a formal ICE agreement - 50 employees, and how many must ask
- gov.uk: business transfers - consulting and informing - direct consultation under 50 employees
- gov.uk: gender pay gap reporting - who needs to report - 250 employees, snapshot dates and deadline
- gov.uk: creating an action plan - voluntary action plans at 250 or more employees
- gov.uk: publish an annual modern slavery statement - the £36 million threshold
- gov.uk: off-payroll working for clients - the small company test
- ICO: the data protection fee - the tiers by staff and turnover
This is general guidance for UK employers and is not legal advice. Take advice on anything contested, unusual or expensive.
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