From 6 April 2026, principal contractors face liability for the compliance failures of their subcontractors under the new Finance Bill provisions. Most of them do not know yet. Their accountant is the person they will expect to have told them.
The Finance Bill 2025-26 introduces Sections 62A and 62B. Together they create a "knew or should have known" test for principal contractors. If a subcontractor in the chain is non-compliant, the contractor can be held liable where they failed to take reasonable care.
The defence is evidence. A contractor who can demonstrate that they checked, found risk, and managed it is in a far stronger position than one who simply trusted the chain.
Most contractors are not yet aware of this. That awareness gap is your opening. When tax law changes, the accountant is the most trusted voice in the room. This is one of those moments.
When a client gets a letter from HMRC, the first question they ask is rarely "what do I do now." It is "why did nobody warn me." A construction client caught by the new provisions will ask that question of their accountant.
You can be the firm that raised it first. The one that understood the exposure before the client felt it, and pointed them to a way of defending themselves. That is the kind of moment that secures a relationship for years.
There is also a recurring revenue line here. Recommending CIS Defence to a client is not a one-off referral. Partners earn for the life of the client relationship. We set out exactly how in the partner pack.
CIS Defence screens a contractor's subcontractors against a set of risk criteria each month. Day rate benchmarking, company risk signals, CIS registration status, and more. Each subcontractor shows as Red, Amber, or Green.
Where a risk is found, the contractor's manager can record a formal, named, timestamped decision to accept and manage it. The platform then generates the HMRC Passport. A PDF evidence pack recording every check run, every risk found, and every decision made.
That Passport is what a contractor would present to HMRC if investigated. It is the difference between "we trusted them" and "here is what we checked, what we found, and what we did about it."
See how the product works in fullThis matters, so we say it plainly. The contractor's own team must be the ones running the checks and making the risk decisions. This is not a technical limit. It is a compliance requirement.
The HMRC Passport records who made each decision and when. For it to stand as evidence of reasonable care, those decisions must be made by named individuals inside the contractor's own organisation. An accountant overriding risk flags on a client's behalf would weaken the defence, not strengthen it.
Your role is advisory, and it is the valuable one. You identify which clients are exposed. You recommend the platform. You help them understand what the outputs mean and what action to take. The action itself is theirs.
You refer the client to us. We handle the demo, the onboarding, and all commercial discussion. We sign and bill the contractor directly. The contractor's own team operates the platform. You receive a commission for the life of that client relationship. No billing admin. No platform access required. No constraint on your own fees.
Best for: practices where construction compliance is part of your advisory work but not your day-to-day operational focus.
For practices with a substantial construction client base that want to own the commercial relationship. You buy licences wholesale and sell them to your clients at your own price. The contractor's team still operates the platform. Available to practices with sufficient client volume. Terms are agreed case by case.
Best for: larger or specialist construction practices that want to build the product into their own service proposition.
Most practices start as an Introducer. We set out the full commercial terms for both routes in the partner pack.
If you have construction clients who should be on this platform, tell us. We can walk you through the product, help you identify which clients are most exposed, and set up the arrangement so your first referral is ready to go.
We will send the partner pack and follow up to answer any questions. No obligation.
CIS Defence solves one narrow, high-consequence problem. Construction supply chain risk. It exists because the cost of getting it wrong is measured in HMRC enquiries, not inconvenience.
Your clients will have others. If you keep running into a compliance or risk problem that no off-the-shelf software handles properly, we can build something for it. The same approach that produced CIS Defence applies to bespoke work. We start with the actual liability, not with features.
See how we build bespoke solutions