HR Software for Small UK Businesses: Build, Buy, or Both?

HR is where "one system for everything" promises go to die. The commodity parts are commodity and should be bought; the parts that follow your own rules are where a bespoke system pays. Most businesses need one of each, connected.

Buy these

• Payroll. HMRC rules change every April. Never build payroll.
• Holiday and absence with standard accrual rules. BrightHR, Breathe, CharlieHR and similar handle this well for small teams.
• Pensions auto-enrolment. Buy, via payroll.
• Basic employee records if that is all you need.

For a business of ten to fifty people whose HR is standard, one of the small-business HR platforms at a few pounds per employee per month is the right answer, and we will say so.

Where off-the-shelf HR breaks

The same three places every off-the-shelf system breaks: your process is not the standard one, the data you need lives in three other systems, or the per-employee price stops making sense at scale. In HR specifically:

Rotas and shift-based workforces

Care, hospitality, security, logistics, retail. Availability, qualifications, minimum staffing per site, fair distribution of unpopular shifts, swap requests, and the cost of each rota against budget. Generic rota tools handle the simple cases; the businesses that come to us have rules the tools cannot express.

Compliance that depends on role and site

Right-to-work checks with expiry dates, DBS renewals, training certificates that lapse, driving licence checks, site inductions. A compliance system that knows which people need which checks, when they expire, and who is not allowed on site tomorrow is a genuine operational tool, and off-the-shelf HR treats it as a document folder.

Onboarding that touches many systems

New starter: contract generated, accounts created, equipment ordered, training assigned, first-week plan issued, manager reminded. If this takes a coordinator two days per hire, a workflow that does it is worth building.

Performance and skills frameworks that are yours

If you have designed your own competency framework or review cycle, generic performance modules will make you flatten it.

The "both" pattern

Keep the platform for payroll, holiday and the employee record. Build the operational HR - rotas, compliance, onboarding workflow, skills - as a custom HRM that reads the employee record from the platform and pushes back what it needs to. Employees still get one login for the day-to-day, and you stop paying for modules that do not fit.

UK compliance considerations for a custom build

• UK GDPR. HR data is high-risk personal data. Data protection impact assessment, retention schedules, access logging, UK hosting, and a documented lawful basis for each category of data. Your developer should be able to talk about this before you ask.
• Right to work. Store the evidence, the check date, the checker and the expiry, and alert before expiry. The system should make the statutory excuse easy to demonstrate.
• Working time. If you build rotas, build the working-time rules in: rest breaks, weekly limits, night work. It is cheaper to enforce them in software than to discover a breach later.
• Holiday for irregular hours. The rules for irregular-hours and part-year workers changed in 2024. If your workforce is shift-based and you build holiday accrual yourself, have it checked.

Cost, briefly

A compliance tracker with expiries, alerts and reporting, connected to an existing HR platform: £8,000 to £18,000. Rota management with rules, swaps and cost reporting: £15,000 to £40,000 depending on how many rules and sites. Full onboarding workflow across several systems: £10,000 to £25,000. These follow the same logic as our CRM cost guide: roles, integrations and data migration move the number.

A worked example: a care provider

Ninety care staff across four services, with rotas built weekly in spreadsheets by three coordinators. Compliance - DBS, right to work, mandatory training, vehicle documents for community staff - is tracked in another spreadsheet and checked before inspections. Payroll and holiday run on a standard platform and work fine.

The build: a rota system that knows each person's qualifications, contracted hours, availability and the minimum staffing rules for each service; that flags working-time breaches before publishing; that lets staff swap shifts within rules from their phones; and that exports approved hours to payroll. Plus a compliance module with expiries and alerts, feeding a "can this person work this shift" check into the rota. The platform stays for payroll, holiday and the employee record, synced nightly.

Cost: upper mid band, phased over four months. Payback: three coordinator-days a week returned, plus the inspection risk that no longer depends on a spreadsheet being up to date.

Employee-facing considerations

Staff will use the system from their phones, often between shifts, on poor connections. That shapes the build: a responsive web app that works on any phone, simple screens, and notifications by SMS or push for the things that matter (shift confirmed, swap approved, document expiring). A native app is rarely necessary for HR tools; see our note on native versus cross-platform if you think yours is the exception.

Getting started without a big bang

Start with the compliance tracker. It is the smallest piece, it stands alone, and it removes the most risk. Rotas come next, once the compliance data is clean, because the rota needs it. Onboarding workflow last, because it touches every other system. Each stage is used before the next is built, which is the pattern that keeps HR projects from becoming eighteen-month programmes.

Questions to settle before scoping

• Which HR platform stays, and does it have an API for employee records? (Most do; check what it exposes.)
• How many rota rules exist, written as sentences? Ten is a small system; fifty is not.
• Which compliance items have expiry dates, and who is responsible for each?
• Will staff use their own phones, and do any of them work somewhere without signal?
• Who in HR or operations will own the system and make decisions about it?

Those five answers are most of a brief. Our guide to briefing a software agency covers the rest, and the answers also tell you honestly whether the off-the-shelf platform you already pay for could stretch to cover it.

Two last points. First, every rota or compliance change should be logged with who made it and when; when a dispute arrives months later, the log is the answer. Second, on data protection: HR systems attract subject access requests, and a system that can produce everything held about one person, cleanly, in a day, saves real money. Ask for it as a feature, not an afterthought, whichever half you build and whichever you buy.

If you are maintaining a spreadsheet for right-to-work expiries or building rotas by hand every week, that is the signal. Describe the process and we will tell you which half to buy and which half to build.