Missing bonding on an EICR: what it means

Missing or ineffective main protective bonding can be a C2 finding when it creates a potentially dangerous shock risk. C2 makes an EICR unsatisfactory. The inspector must establish what is wrong; a note saying that no wire was visible does not prove that a bond is required or missing.

The electrician checks the incoming service, the earthing arrangement, the connection and test results. Plastic pipes and altered pipework can make a visual guess unreliable. Main bonding and supplementary bonding are different protective measures.

Main protective bonding helps reduce a dangerous difference in voltage between metal parts that someone could touch at the same time. It connects the relevant conductive parts to the main earthing terminal.

It is not simply a way to use gas or water pipes as a fault-current return path. Earthing, circuit protective conductors and bonding have related but different jobs. The electrician assesses them as a protective system.

A metal part may need main bonding if it can bring a voltage, usually earth potential, into the building from outside the electrical installation. The technical name is an extraneous-conductive-part.

Not every metal pipe meets that definition. A plastic incoming service and copper pipes inside a flat need proper assessment. Do not add or remove a bonding wire just because of how a pipe looks.

Main bonding concerns relevant conductive parts entering the installation. Supplementary bonding connects particular accessible metal parts where the protective requirements call for it.

A missing bathroom cross-connection is not automatically the same as missing main bonding. The inspector checks the installation and the applicable conditions before deciding whether work is needed.

The observation should identify the affected part, what was found and why it matters. Read the code beside that observation, together with any inspection limits and test results.

Ask whether the bond was proved absent or ineffective, or could not be inspected. These are different findings. A photo of a pipe or clamp cannot establish the whole protective arrangement.

• Whether the part can introduce earth potential and is therefore truly extraneous.
• The earthing arrangement and the condition of the main earthing terminal and conductor.
• Continuity, size and termination of any existing bonding conductor.
• The location of the connection relative to the service entry, meter, branches and insulating sections.
• Accessible Class I equipment and conductive parts that could be touched simultaneously.
• Alterations to gas, water or heating services since the electrical installation was last inspected.
• Access limitations caused by boxing, locked intake rooms, fitted kitchens or communal service routes.

The code depends on the confirmed defect and the risk. A missing required main bond can justify C2. A recommended improvement or a request for investigation needs its own recorded reason.

FI means further investigation is needed. Under the A4:2026 format it does not, by itself, make an EICR unsatisfactory. Earlier report formats may differ. It is still important to act on any investigation the report requires.

In a converted house, several flats may share a water service while having separate electrical supplies. A clamp under one sink may not provide the required main bond for a particular flat.

In a refurbished home, copper pipework inside may connect to a plastic incoming service. In a block, heating pipes can cross flat boundaries. These situations need inspection and testing, with the managing agent involved where shared access is needed.

A visible clamp does not prove that a bond works. The wire may be damaged, incorrectly connected or unsuitable for the installation. A plastic section of pipe does not prove that an existing bond can safely be removed.

Do not disconnect green-and-yellow conductors or fit temporary wires. Ask a competent electrician to establish what is required and test the arrangement.

If a required bond is missing or ineffective, the electrician agrees a suitable conductor route and connection. Meter cupboards, service entry points and shared building areas may need access.

After the repair, the contractor checks the connection and protective arrangement and provides the right paperwork for the work. A new clamp on its own does not prove that the observation is resolved.

Where the rented-sector rules require remedial or further investigative work, it generally needs to be completed by a qualified person within 28 days of the inspection and test, or sooner if the report says so. Read the report and current rules for the property. The reasonable-steps provisions may matter where access is prevented.

Send the full report to the contractor and keep the access correspondence and completion evidence. A future renewal booking is not a substitute for dealing with the present finding.

Send the complete report and its observation numbers. Tell us where the gas meter, water stopcock and electrical intake are, and whether services are boxed in or shared.

Arrange keys or permission for communal cupboards. Ask for one quote for the repair scope you agree, including any investigation, access work, testing and completion paperwork. Agree who handles decoration or joinery before work starts.

Use your full report to request a bonding-work quotation and identify the service or circuit named in the observation.

Ask the inspector which part needs bonding, how that was established and what evidence supports the code. If investigation is needed, ask what it will check.

Do not alter the bonding yourself. If taps, pipes or appliances cause tingling or shocks, stop using the affected equipment and seek urgent professional help. Heat, arcing and damaged intake equipment also need a prompt safety response.

Sources checked on 3 October 2026. Read this guidance alongside your own EICR: its edition, observations, extent and limitations matter. Ask a qualified electrician to assess the findings at your property.

Building services, wiring arrangements and access differ substantially across London property types. The examples explain why judgement varies; they do not prescribe a code remotely. Current standards, reliable test evidence and the competent person's assessment of the actual installation determine whether bonding is required and how an observation is classified.

This article was editorially reviewed on 2026-10-03. It provides general operational guidance for London property decision-makers and is not personalised legal advice.

Electrical classification on an EICR depends on the installation, the observations recorded and competent professional judgement. Always read your own report and seek competent advice for your property.