Do Subcontractors Pay 40% Tax? UK CIS FAQ for Construction Subcontractors
10 March 2026•5 min
This FAQ explains what “best project management” really looks like on UK construction projects, how to apply the 80/20 rule on site, and the common types of project managers you’ll encounter. It’s written for busy construction professionals who need practical, repeatable ways to control programme, cost, quality, and risk—without drowning in admin.
Frequently Asked Questions
What's the best project management?
In construction, the “best” project management is the approach that consistently delivers a safe, compliant job on time, within budget, and to spec—while keeping the supply chain aligned. It’s less about a fashionable methodology and more about disciplined controls, clear communication, and real-time visibility.
On a UK site, best practice typically means:
<ul class="my-4 space-y-2"><li class="ml-4 list-disc list-inside">A clear scope and change control: RFIs, variations, and design updates are captured and agreed before work proceeds.</li><li class="ml-4 list-disc list-inside">A realistic programme: short-interval planning (weekly/daily) tied to actual labour, plant, and material constraints.</li><li class="ml-4 list-disc list-inside">Strong commercial grip: early warnings, valuation readiness, and evidence for compensation events/variations.</li><li class="ml-4 list-disc list-inside">Quality and compliance built-in: inspections, test plans, and sign-offs recorded as the work is done.</li><li class="ml-4 list-disc list-inside">A single source of truth: drawings, RAMS, permits, snag lists, and correspondence all traceable.</li></ul>Example: on a school refurbishment, ceiling works slip because M&E first fix clashes weren’t spotted. The best PM process catches it early using coordinated lookaheads, raises an RFI, agrees the revised sequence with the M&E subcontractor, and updates the programme and site diary with evidence.
SiteSamurai supports this by centralising day-to-day site controls—digital daily logs, tasks, snagging, approvals, and document tracking—so foremen, QSs, and PMs aren’t chasing WhatsApp threads or outdated drawings. You get clearer accountability, faster decisions, and fewer disputes because the record is complete and time-stamped.
What is the 80/20 rule for project managers?
The 80/20 rule (Pareto Principle) means a small number of causes typically drive most outcomes. For project managers, it’s a way to focus effort where it actually shifts programme, cost, and risk—rather than spending hours on low-value admin.
On UK construction projects, the “vital 20%” often includes:
<ul class="my-4 space-y-2"><li class="ml-4 list-disc list-inside">A few high-risk activities: steelwork erection, concrete pours, shutdown tie-ins, or waterproofing details.</li><li class="ml-4 list-disc list-inside">A handful of key subcontractors: the trades that dictate follow-on works (e.g., M&E, drylining, façade).</li><li class="ml-4 list-disc list-inside">Recurring constraints: access, permits to work, deliveries, design information release, and inspections.</li><li class="ml-4 list-disc list-inside">The biggest commercial drivers: variations, delays, and rework due to coordination issues.</li></ul>Example: on a residential block, 80% of delays might come from just two issues—late kitchen deliveries and repeated snagging on fire stopping. A PM applying 80/20 would:
<ul class="my-4 space-y-2"><li class="ml-4 list-disc list-inside">Prioritise procurement tracking and delivery booking for kitchens</li><li class="ml-4 list-disc list-inside">Increase targeted QA inspections on fire stopping with photo evidence</li><li class="ml-4 list-disc list-inside">Hold short, focused coordination huddles with the responsible subcontractors</li></ul>SiteSamurai helps you apply 80/20 by making the key signals visible: outstanding actions, overdue approvals, recurring snags, and blocked tasks. Instead of trawling emails, you can use dashboards and filtered lists to concentrate on the small set of items that will protect the critical path, reduce rework, and strengthen your audit trail for valuations and claims.
What are the 4 types of project managers?
In practice, “types” of project managers usually describes how they lead and control work, rather than their job title. In construction, four common types you’ll recognise are:
<ul class="my-4 space-y-2"><li class="ml-4 list-disc list-inside">The Planner/Controller: programme-led, detail-focused, strong on lookaheads, sequencing, and constraints management.</li><li class="ml-4 list-disc list-inside">The Commercial/Risk Manager: prioritises cost certainty, change control, and contract compliance (NEC/JCT), with tight records.</li><li class="ml-4 list-disc list-inside">The Site/Delivery Manager: boots-on-the-ground, productivity-driven, excels at subcontractor coordination, logistics, and short-interval planning.</li><li class="ml-4 list-disc list-inside">The Stakeholder/Client Manager: relationship-led, strong communicator, manages expectations, approvals, and handover requirements.</li></ul>Example: on a fit-out in a live office, the Delivery Manager type will focus on night works, permits, and interfaces with building management. The Commercial/Risk Manager type will ensure any out-of-hours premiums, scope creep, or access restrictions are captured as variations with supporting evidence.
The best construction PMs flex between these styles depending on the project stage:
<ul class="my-4 space-y-2"><li class="ml-4 list-disc list-inside">Early stage: Stakeholder + Commercial focus (scope, approvals, contract terms)</li><li class="ml-4 list-disc list-inside">Mid-delivery: Delivery + Controller focus (production, constraints, critical path)</li><li class="ml-4 list-disc list-inside">Close-out: Controller + Stakeholder focus (snagging, O&M manuals, handover)</li></ul>SiteSamurai supports all four styles by providing a shared system for tasks, snags, documents, site diaries, and approvals. Whether you’re chasing completion of fire door checks, managing design queries, or proving delay impacts, the team works from the same live information—reducing friction between site, commercial, and client-facing priorities.
Choosing the “best” project management in construction comes down to disciplined controls, focused priorities, and a reliable site record. If you want to cut admin, improve visibility, and keep your programme and commercial position protected, talk to SiteSamurai about streamlining your site management from one platform.