Your London agency runs employees on BambooHR and the freelance bench on a spreadsheet nobody trusts
Custom HR (Human Resources) software in London typically costs £45k to £140k over 4 to 7 months. You build custom when off-the-shelf HR tools model permanent employees well and your actual workforce, the freelance bench, the IR35 calls, the right-to-work and visa tracking, doesn't fit their boxes. For a London agency or services firm, the trigger is the day a mis-tracked IR35 status or an expired visa becomes a real liability.
BambooHR, Workday, and Gusto are built around a clean permanent-employee model: one person, one contract, one set of dates. Your London agency doesn't work like that. You run a core team plus a rotating freelance bench, contractors whose IR35 status you have to assess and document, and a workforce that includes visa holders whose right-to-work and expiry dates you are legally obliged to track. The off-the-shelf tool has no real home for any of it, so it lives in spreadsheets.
That gap is a liability, not just an inconvenience. A freelancer mis-categorised under IR35, an expired right-to-work check, a visa renewal missed, each carries real financial and legal exposure in the UK. Your HR lead manages the highest-risk parts of the workforce in the tool the official HR system can't see, which is exactly the data you most need to be reliable and auditable.
What breaks first in London
- BambooHR and Workday model permanent staff but have no real structure for a freelance bench
- IR35 status assessment and documentation lives in spreadsheets, creating tax exposure
- Right-to-work and visa-expiry tracking is manual and easy to miss, a legal liability
- Contractor onboarding, rates, and availability sit outside the official HR system
The fix: hr built for London, not rented
A London agency's workforce is a mix of permanent, freelance, and contract people with UK-specific compliance, IR35, right-to-work, visa tracking, that no off-the-shelf HR tool was designed to hold. Custom HR software models your actual workforce: the bench with its rates and availability, documented IR35 assessments, and automated right-to-work and visa-expiry alerts. The riskiest, most compliance-sensitive parts of your workforce move out of spreadsheets into an auditable system, which is exactly where they need to be.
What hr costs in London
| Project scope | Typical cost | Timeline |
|---|---|---|
| Custom HR module for freelance bench + IR35 | £45k to £85k | 4 to 5 months |
| Full custom HR platform with compliance tracking | £90k to £140k | 5 to 7 months |
| Right-to-work and visa-tracking module only | £30k to £55k | 3 to 4 months |
The capability list that earns its budget
HR services we deliver in London
The engagements London teams bring us most often: Workday integration, leave management, performance management software, custom HR software and HRIS development.
Exactly what you get
HR software that models the workforce you actually have, not the permanent-only one BambooHR assumes. Your freelance bench with rates, skills, and availability lives in the system. IR35 assessments are documented with an audit trail HMRC would accept. Right-to-work and visa expiries trigger alerts before they become liabilities. And contractor onboarding follows a recorded process. The riskiest, most compliance-sensitive parts of your London workforce move out of spreadsheets and into an auditable system.
How to choose a developer in London
Hire a team that understands UK employment compliance, not just HR data models, because IR35, right-to-work, and visa tracking are where the real liability sits. Ask how they'd document an IR35 assessment so it survives an HMRC query, and how visa-expiry alerts actually fire. A partner who treats freelancers as ordinary employee records has missed the point. Connect the HR build to your project management software and internal tools so resourcing draws on the same bench data the compliance team relies on.
- !They've never handled IR35 or right-to-work logic; ask for a UK agency reference
- !They treat freelancers as just another employee record; ask how they model the bench
- !No audit trail for status decisions; ask how an HMRC IR35 query would be answered
- !Visa-expiry tracking is hand-waved; ask how alerts are triggered and to whom
- !Quote without understanding your workforce mix; ask for a workforce audit first
Teams investing in hr in London usually scope it next to pos, warehouse management, helpdesk & ticketing, since these systems share data and budgets.
Rohan advises mid-market and enterprise teams on ERP, CRM and custom software, and has led delivery on dozens of business-software builds.
Writes for Digital Heroes, shipping business software for 2,000+ brands across 55+ countries since 2017.
Frequently asked questions
Why can't BambooHR handle our freelancers?
BambooHR and similar tools are built around the permanent-employee model, one person, one contract, one set of dates. A freelance bench with variable rates, availability, and IR35 status doesn't fit, so it ends up in spreadsheets. Custom HR software models the contingent workforce directly.
How does custom HR software help with IR35?
It provides a structured assessment workflow that documents each status decision with an audit trail, so if HMRC queries a contractor's status you can show how and why it was determined. Spreadsheets can't give you that defensible record.
Can it track right-to-work and visa expiry?
Yes, and that's often the strongest reason to build. The system monitors right-to-work documents and visa expiry dates and alerts the right people in advance, preventing the missed-deadline liabilities that manual tracking creates.