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IT and telecoms
Yes. If you design, specify or advise on networks for clients, you need professional indemnity insurance. A network design is a set of assumptions about traffic, resilience and security that the client then pays others to build. When those assumptions are wrong, the loss arrives as outages, rework or a breach that spread through a flat network, and the claim comes back to the designer. PI usually responds to that allegation. Public liability does not.
Part of: Professional indemnity for IT professionals
In short
Network design consultants are judged on the design basis: the capacity, resilience and security requirements they set, and whether the architecture meets them. Undersized links, a single point of failure in a design sold as resilient, and segmentation that lets an attacker move freely are the classic allegations. PI covers negligent design and advice, subject to the policy terms. Cyber insurance usually covers incidents in your own systems, which hold client diagrams, rule sets and credentials. If you also resell equipment or receive vendor incentives, tell your insurer: it changes both your duty of independence and how the policy treats faulty kit.
Last reviewed 5 October 2026 by the Apex professional indemnity team.
A network design consultant’s product is the architecture: topology, addressing, routing, wireless coverage, security zones and the bill of materials, plus the reasoning behind each choice. Someone else usually installs it. If the design is wrong, the installer can build it perfectly and the client will still suffer.
The losses are financial. Rework and extra equipment, downtime across sites, staff who cannot work, premature replacement of kit that was never going to cope, and the cost of an incident that a better design would have contained. Public liability (PL) insurance covers accidental injury and property damage, such as a ceiling tile broken during a site survey. It does not cover a design that does not perform.
Professional indemnity (PI) insurance, known in the technology market as technology errors and omissions cover, protects you against liability for negligent design, specification and advice, and pays to defend the claim, subject to the policy terms. If you design and also install or configure, describe both to your insurer, because the boundary between design error and workmanship is where disputes start.
The scenarios below are illustrative. They show the kind of allegation network designers face, not real claims or outcomes.
Each is about the quality of design or advice. None involves the accidental damage that PL is built for.
Many network design disputes come down to whose assumption was wrong. A clear, agreed design basis is the most effective protection you have.
Independence is often what a network design consultant sells. Clients hire you instead of a reseller because they want advice that is not shaped by margin. If you hold partner status, earn rebates or register deals with a vendor, that can be legitimate, but it changes what you must disclose.
The BCS Code of Conduct, which applies to members of BCS, The Chartered Institute for IT, asks members to seek to avoid any situation that may give rise to a conflict of interest with their “relevant authority”, the person or organisation with authority over their professional work, and not to misrepresent or withhold information on the performance of products, systems or services. Courts and experts will ask the same questions.
If you also supply the equipment, tell your insurer. PI responds to negligent advice; it usually excludes defects in products you sell, which need product liability cover and the manufacturer’s warranty. A claim that you recommended a product because of an incentive may still be defended as a negligence claim, but dishonest conduct is normally excluded.
| Standard or framework | What it covers | Why it matters to your PI |
|---|---|---|
| ISO/IEC 27033-2:2012 | Guidelines for organisations to plan, design, implement and document network security. | The most direct international reference for security architecture decisions. |
| ISO/IEC 27001:2022 | Requirements for an information security management system. | Certified clients expect your design to support the controls they have committed to. |
| NCSC Cyber Assessment Framework, principle B4 | Security should be designed into the network and information systems supporting essential functions, with systems segregated into appropriate security zones. | For clients under the NIS Regulations or in critical national infrastructure, your design becomes evidence in their assessment. |
| Cyber Essentials requirements v3.3 (NCSC, April 2026) | Firewalls must block unauthenticated inbound connections by default, default admin passwords must be changed, and admin interfaces must not be reachable from the internet unless there is a documented business need and they are protected by MFA or an IP allow list. | A design that leaves management interfaces exposed fails a baseline many clients work to. |
None of these is a law, but each is the kind of benchmark an expert witness reaches for when asked what a competent designer would have done.
| Usually covered by PI | Often excluded or limited | Needs a different policy |
|---|---|---|
| Negligent capacity, resilience, addressing and routing design | Defects in equipment you resold | Liability for products you supply (product liability) |
| Security architecture errors, such as poor segmentation or firewall policy design | Contractual guarantees of uptime or performance | Injury or damage during site surveys (public liability) |
| Negligent wireless surveys and predictive models | Fee disputes and the cost of reworking your own design | An attack on your own systems (cyber) |
| Careless vendor selection or lifecycle advice | Dishonest or deliberately misleading recommendations | Injury to your own staff (employers’ liability) |
| Defence costs, including network forensic experts | Circumstances known before the policy started | Survey equipment lost or damaged (equipment insurance) |
Cover is always subject to the insurer’s acceptance and the policy terms. Check that the policy describes network design and security architecture as part of your professional business.
When a client is breached, its cyber insurer pays first and then looks for someone else to recover from. If the attacker moved through a network you designed, expect the question to be whether your segmentation, remote access design or firewall policy was negligent. That is a PI claim, so check your PI wording does not carry a broad cyber exclusion that removes cover for any claim connected to a cyber event, even when the allegation is about your design.
Your own systems are a target too. Network diagrams, firewall rule sets, VPN configurations and admin credentials from implementation work are exactly what an attacker wants. A breach of your systems could expose several clients at once. Cyber insurance covers your incident response and, on many wordings, liability to clients harmed by the compromise. The cleanest position is PI and cyber written to fit together, ideally with the same insurer.
Enterprise and public sector clients usually set a PI limit in their contracts. Size it to what your design controls: an infrastructure refresh across dozens of sites can produce a claim far larger than your fee. Check whether the client wants each and every claim or aggregate cover.
PI is claims-made, so the policy in force when the claim is made responds. Network designs are tested slowly: capacity problems surface as the business grows and security weaknesses surface when an attacker finds them, often years after your involvement. Keep cover continuous, protect your retroactive date, and buy run-off cover if you stop trading.
A complete proposal gets better terms than a bare one, and a broker can only present what you tell us. Have these ready:
Speak to a broker
PI for network design consultants, placed by a named broker
Start the online proposal and save it as you go, or leave your number and a named broker will call you back, usually the same working day.
Apex Insurance Brokers is an independent insurance broker based in Bristol, established in 2009 and authorised and regulated by the Financial Conduct Authority. We are not tied to one insurer: we work with over 30 markets, including Lloyd’s syndicates through wholesale brokers, and every client has a named broker who handles the placement, mid-term changes, certificates for clients and the renewal.
Yes. If a capacity, resilience or security decision in your design causes outages, rework or a breach, the client’s loss is financial and the claim is for negligent design. PI covers those allegations and your defence costs, subject to the policy terms. Public liability does not.
No UK law requires network design consultants to hold PI. In practice enterprise clients, public sector buyers and main contractors require it in contracts, usually with a minimum limit, and some ask for cover to continue for years after the project ends.
Not for changes you never approved, but you need records to show it. Keep the as-designed drawings, note any deviations you discover, and be careful about signing off installations you did not inspect. If you certify the finished network, your liability can extend to what was built.
It can. A client, or its cyber insurer, may allege your segmentation or remote access design was negligent. That is a PI claim, subject to the terms. Check your PI wording does not exclude all claims connected to a cyber event, and hold cyber cover for your own systems.
Usually not. PI responds to negligent design and advice; defects in equipment you supply are normally a product liability matter, backed by the manufacturer’s warranty. Tell your insurer how your turnover splits between consultancy and resale so both covers are arranged correctly.
Usually, if the work is within your declared professional business and subject to the terms, but the client can still allege the method was inadequate for the building. Explain what a predictive model cannot show, recommend a validation survey where it matters, and record the client’s decision if it declines.
Apex arranges professional indemnity insurance for network design consultants across the UK. Tell us about your work and we’ll find cover that fits. Or call 0117 325 0027.
Start your PI proposal Call 0117 325 0027Apex Insurance Brokers Limited is authorised and regulated by the Financial Conduct Authority. Registered in England and Wales, company number 07014570. This page is general information, not advice on your individual circumstances. Cover is always subject to the insurer’s acceptance and the policy terms, and this page does not guarantee that cover will be available or on what terms.
