Best HR Software for UK Small Businesses 2025

Small UK businesses — under 50 employees — have different HR software needs from enterprise organisations. You do not need 200 configuration options. You need a system that handles the essentials compliantly, does not require a dedicated HR technology team to maintain, and scales as you grow without a rip-and-replace exercise.

The essentials for a UK small business HR platform are: employee records and documents; leave and absence management; ERA 2025 compliance features including day one rights and the changes to SSP; onboarding including right to work checks; payroll including PAYE, NI, pension auto-enrolment, and RTI submission. Some platforms offer most of these — the question is whether payroll is native or requires a separate integration.

Mellow is designed specifically for this segment. From £4 per employee per month at the Essentials tier, scaling to payroll-inclusive pricing at Professional. It is self-service: implementation does not require a consultant, and your first employee can be onboarded the day you sign up. For businesses that want HR and payroll in one place — with ERA 2025 compliance built in — it is worth evaluating alongside the better-known names in this space.