Your first HR hire in the United Kingdom: when and who
Reviewed by Mellow Editorial Team, HR & payroll content team
Bringing in your first dedicated HR person is one of the clearest signals that a business is maturing — but timing it wrong in either direction costs money, compliance risk, or both. Here is how to think through the decision.
When does HR become a full-time job?
There is no universal headcount threshold, but a practical working rule is this: once managing people takes more than a quarter of a senior leader's working week on a recurring basis, you are subsidising HR work with expensive founder or director time.
More concretely, watch for these triggers:
- Headcount around 15–25 employees. Below this, a founder or office manager handling HR with good software is usually viable. Above it, the volume of queries, contracts, onboarding tasks and absence management tends to tip into unmanageable.
- Rapid hiring. If you are adding five or more people a month, the administrative load scales faster than headcount alone suggests.
- Regulatory exposure. The Employment Rights Act 2025 has strengthened day-one rights for employees, meaning the cost of a procedural error — even in the first week of employment — is higher than it was. If nobody in your business is confident interpreting employment law, that is a risk worth pricing.
- Cultural inflection points. A first office, a first round of redundancies, a merger or acquisition — these are moments when the absence of HR expertise tends to surface badly.
If you are still below these thresholds but need support, an HR consultant on a retained basis or a fractional HR director can bridge the gap without a permanent salary commitment.
Generalist, specialist or HR business partner?
For a first hire, a generalist is almost always the right call. You need someone who can write a contract in the morning, handle a disciplinary process in the afternoon and brief a manager on auto-enrolment obligations before leaving. Depth in a single area — learning and development, say, or reward — is a luxury that comes later.
The job title matters less than the scope. Whatever you call the role, be explicit in the job description about what it owns:
- Employment contracts and offer letters
- Onboarding and offboarding processes
- Absence, holiday and leave administration (statutory annual leave is 5.6 weeks, equivalent to 28 days including bank holidays for a five-day week worker — a surprisingly common source of disputes)
- Disciplinary and grievance processes
- Liaison with payroll, whether in-house or outsourced
- Keeping the employee handbook current
If the role also owns payroll, budget for either a more senior hire or dedicated payroll software. Combining HR and payroll in one person's remit is common in smaller businesses but increases the risk of errors going unnoticed.
What experience and qualifications should you require?
CIPD (Chartered Institute of Personnel and Development) membership is the standard professional benchmark in the UK. A Level 5 Associate Diploma in People Management is generally considered the minimum for a standalone HR role; Level 7 is post-graduate equivalent. CIPD status matters partly because it signals self-directed continuing professional development — employment law changes frequently enough that a generalist who stopped learning two years ago can quickly become a liability.
Practical experience of UK employment law is non-negotiable. If you are hiring someone who has worked exclusively outside the UK, factor in a learning curve on specifics: IR35 rules, TUPE obligations, the distinction between workers and employees, and the RTI payroll reporting regime are all areas where UK practice differs meaningfully from elsewhere.
Cultural fit matters more in HR than in most roles, because this person will hold sensitive information about every employee in the business and will often be the one delivering difficult news. Assess how they handle ambiguity and how they talk about previous employees — loose confidentiality in an interview is a red flag.
How to structure the hire itself
Set a salary range before you post the role, not after. HR professionals are skilled at benchmarking compensation and will notice if you have not done so, which undermines credibility from the start. Salary data from the CIPD, Glassdoor and sector-specific recruiters will give you a realistic range for your location and the seniority you need.
Write the employment contract carefully. Given that this person will likely be reviewing other employees' contracts, any inconsistency or ambiguity in their own will be noticed immediately. If your template contracts need updating to reflect current legislation — including the strengthened day-one rights under the Employment Rights Act 2025 — do that before, not after, you make this hire.
Consider a three-month probation with structured check-ins at weeks four and eight. An HR hire who is not the right fit is a particularly sensitive situation to unwind, both practically and in terms of the information they hold. Clear milestones — an updated handbook by week six, a payroll audit by week eight — give you objective reference points.
Handover: what they need to inherit
Before the first day, gather everything they will need to take ownership of:
- All current employment contracts and any side letters
- Payroll records and the contact at your payroll provider
- Pension scheme details and auto-enrolment records (minimum employer contribution is 3% of qualifying earnings)
- A log of any open or recent disciplinary, grievance or absence cases
- Any outstanding compliance actions — P11Ds are due by 6 July, P60s by 31 May
A clean handover signals that you take the function seriously. It also means your new HR lead can spend their first weeks building, not excavating.
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