The problem:
You are running electrical packages on 4-to-12-month projects, not one-day service calls. The main contractor wants a monthly application in their format by the 25th, a daily site diary, RAMS before first fix, digital test certificates at commissioning, and CIS paperwork for every subbie sparks you bring on. Meanwhile your office is chasing the Pay Less Notice window, re-verifying subbies with HMRC, and trying to keep the programme against a slipping groundworks package. Job-ticketing tools built for EICRs and reactive faults have no concept of a monthly valuation cycle, retention, or s.111 — and enterprise platforms are priced for head contractors ten times your size.
The fix:
Site Samurai is project-based construction software built for UK subcontractors on long schemes. Applications for Payment track the Construction Act 1996 s.111 Pay Less Notice window from certification date and serve the application to the main contractor through a no-login client portal. CIS verification hits HMRC for every subbie, stores the UTR/NI encrypted, and applies 0%, 20% or 30% to every payment line automatically. RAMS cover 18th Edition risk with digital sign-off by every operative on site. Site diary captures cable routes, test readings and photos against the day, and the commissioning snag register drives defects to close-out before PC. Unlimited users on every plan from £99/month.
Last reviewed: 21 April 2026
TL;DR
Site Samurai is project-based construction software built for UK subcontractors on long schemes. Applications for Payment track the Construction Act 1996 s.111 Pay Less Notice window from certification date and serve the application to the main contractor through a no-login client portal. CIS verification hits HMRC for every subbie, stores the UTR/NI encrypted, and applies 0%, 20% or 30% to every payment line automatically. RAMS cover 18th Edition risk with digital sign-off by every operative on site. Site diary captures cable routes, test readings and photos against the day, and the commissioning snag register drives defects to close-out before PC. Unlimited users on every plan from £99/month.
Eight-month care home fit-out with five sparks on site, a main contractor wanting a daily site report and snag list in their own format, and a £180k application due by the 25th every month.
The application goes out late because someone is still pulling variation sign-offs out of email threads and WhatsApp, and by the time certification lands the s.111 Pay Less window is already half gone.
Three-phase social housing refurb: you bring on two 2x2 sparks subcontractors mid-project, each needing HMRC verification before their first payment and RAMS for live working on occupied flats.
Subcontractor packs live in a Dropbox folder nobody can find, CIS verifications are re-run from a spreadsheet nobody owns, and when HMRC flips a subbie from verified to 30% unmatched nothing cascades to the unpaid lines already in the system.
Education second-fix over the summer holiday with a hard PC date: ten circuit tests, EICs, and commissioning snags have to be closed inside four weeks against a slipping joinery programme.
Test results are scribbled in a pad, photos sit on three different phones, and snag sign-off is a printed list that keeps getting re-emailed in the wrong version — you cannot prove close-out against the contract terms.
Multi-storey new-build: your operatives are pulling containment on floor 4 while first-fix is on floor 2 and second-fix is on floor 1, with a principal contractor asking for 18th Edition risk assessments and toolbox talk evidence every Monday.
RAMS get re-used from the last job with the wrong site address, toolbox talks happen but the signed attendance sheet is in the van, and a CDM audit turns into a scramble for paperwork you already own but cannot produce.
A 40-plot housing scheme where the main contractor issues variations through instruction sheets, and the programme for M&E first-fix is shifted by the brickies every fortnight.
You know the project is losing money but you cannot tell which plots, because the variations, dayworks and extra labour are tracked separately from the application — so monthly valuation is a guess rather than a number.
Year-end: HMRC CIS300 is due, Xero reconciliation is three months behind, and the accountant wants a clean project P&L for the two schemes that completed in Q4.
Everything lives in four systems — an accounts package, a spreadsheet, a shared drive and a WhatsApp group — and producing a project-level P&L takes a week of office time you do not have.
Applications for Payment with s.111 Pay Less Notice tracking
See workflowDraft the application against the contract sum and registered variations, send it to the main contractor through a client portal (no login required), and watch the s.111 window from certification date — the dashboard flags the Pay Less deadline seven days out so nothing slips into deemed payment territory.
CIS verification, deduction and monthly return
See workflowVerify every subcontract sparks against HMRC, store UTR and NI encrypted, and apply the returned rate — 0% Gross Payment Status, 20% verified net or 30% unmatched — automatically to every payment. Re-verification cascades forward to unpaid amounts, so an HMRC status change does not leave you applying the wrong deduction on a certified line.
Subcontractor onboarding and insurance monitoring
See workflowEvery subbie sparks goes through a single onboarding pack — insurances, H&S declaration, RAMS review, CIS status — and expiring certificates surface on the dashboard before they lapse rather than when you notice a claim.
RAMS builder with digital sign-off (Professional plan)
See workflowBuild method statements for 18th Edition (BS 7671) live-working, isolation, containment and test-and-inspection tasks, then collect digital sign-off from every operative on site before first fix. The audit trail is there for the principal contractor the day they ask.
Site Diary with photo attachments
Daily log of labour, plant, deliveries, test readings, cable routes and progress photos tagged to the project and date. When the main contractor queries a day six weeks ago, the evidence is already filed against the application and the programme.
Toolbox Talks with digital attendance and Construction Phase Plans
Toolbox talks are delivered and signed on a phone, attendance is against the named operative, and CDM 2015 Construction Phase Plans live next to the project rather than in a shared drive.
Purchase Orders, GRNs and 3-way matching (Professional plan)
See workflowRaise POs for cable, accessories and fittings against a project budget, receipt goods with photo evidence on site, and match supplier invoice to PO and GRN before it goes to pay. Committed-cost visibility is against the project, not buried in the accounts package.
Retention tracker and project P&L
Every application records retention deducted and release dates against Practical Completion and Defects Liability. The project P&L rolls applications, variations, POs, subcontract cost and labour into a single number rather than a reconstructed spreadsheet at year-end.
Two-way Xero and Sage sync with CIS300
Supplier invoices, subbie payments and CIS deductions post to the accounts package with the right coding, and the monthly HMRC CIS return is produced from the same data that paid the subbies — not reconstructed from a separate spreadsheet.
Electrical subcontracting in the UK sits inside a specific stack: JIB grading and wage rates for directly-employed operatives, 18th Edition (BS 7671) as the wiring standard, NICEIC or NAPIT registration for the business, ECA membership where you hold it, and Building Regulations Part P for notifiable domestic work. On top of that, every project you take from a main contractor carries HMRC CIS, the Construction Act 1996 (HGCRA as amended) including the s.111 Pay Less Notice regime, CDM 2015 as the principal contractor's compliance spine, RIDDOR for reportable incidents, and either JCT 2016 or NEC4 as the parent contract your subcontract flows down from. Site Samurai is built around these primitives — applications are certified and tracked against s.111 dates, CIS deductions use HMRC-returned statuses rather than a guess, RAMS hook to 18th Edition risk categories, and CDM Construction Phase Plans live next to the project they relate to.
14-day free trial, no card required. Unlimited users on every plan. Pricing is per organisation, not per head.
Starter
£99/month
Applications for Payment with s.111 tracking, CIS verification and deduction, subcontractor onboarding, site diary, toolbox talks, client portal.
See full planProfessional
£199/month
Everything in Starter plus RAMS builder, CDM 2015 Construction Phase Plans, purchase orders with 3-way matching, NEC early warnings, dayworks, P6-style programme, Xero and Sage sync.
See full planEnterprise
£699/month
Everything in Professional plus unlimited AI RAMS and toolbox generation, voice-first site capture with offline queue, WIP and monthly management accounts, SSO/SAML, LazyQs AI contract review.
See full planApplications for Payment software
Monthly applications, variations, retention and Construction Act s.111 Pay Less Notice tracking — the core commercial workflow for electrical packages.
CIS management software
HMRC verification, encrypted UTR/NI storage, automatic 0%/20%/30% deduction and the monthly CIS300 return.
CIS verification software
Stand-alone CIS verification workflow with re-verification cascades to unpaid amounts.
Construction RAMS software
RAMS builder with digital sign-off for 18th Edition risk categories, live working and containment.
Subcontractor onboarding software
Single pack for insurances, H&S declaration, RAMS review and CIS status with expiry alerts.
Purchase order software
POs, GRNs and 3-way matching against project budgets — the basis of committed-cost visibility.
Incident reporting software
RIDDOR-ready incident capture with photo evidence and CDM 2015 audit trail.