Every EV charger installation requires formal inspection, testing, and certification before use. UK law requires an Electrical Installation Certificate (EIC) from the installer, confirming the work meets BS 7671 standards.
Building regulations approval is always required when installing an EV home charger, as the work is deemed ‘notifiable work’ involving the creation of a new circuit. Skip certification and you risk insurance problems, safety hazards, and potential fines during property sales.
Testing procedures and BS7671 verification
The EIC confirms that electrical work has been designed, built, inspected, and tested in accordance with BS 7671, the UK’s national wiring regulations (IET Wiring Regulations, Eighteenth Edition).
Professional testing follows a structured sequence. Visual inspection comes first, checking cable routing, terminations, appropriate cable sizes, and equipment condition. Outdoor installations require weatherproof cabling and IP-rated fittings, so inspectors verify that the IP ratings match the environmental exposure.
Continuity testing verifies protective conductor integrity. The installer must verify that the resistance between the main earthing terminal and Earth doesn’t exceed 70V RMS in the event of an open circuit on the PEN supply conductor. This requirement addresses safety concerns with TN-C-S earthing systems, where combined neutral-earth configurations can create dangerous voltages if the PEN conductor fails.
Insulation resistance testing applies high voltage (typically 500V DC for 230V circuits) to stress-test insulation. Section 9 of the Fifth Edition IET Code includes additional guidance for inspection and testing procedures. Readings must exceed 1.0 megohm for circuits up to 500V. Lower readings indicate insulation faults from water ingress, cable damage, or manufacturing defects.
Polarity verification confirms live and neutral are correctly connected throughout. Reversed polarity creates serious safety issues where circuits remain live even when switched off.
Earth fault loop impedance testing measures the complete fault current path. Results must show that protective devices will disconnect within BS 7671 time limits (typically 0.4 seconds for socket outlets).
RCD testing must follow BS 7671:2018+Amd1:2020, Regulation 643.8, including any RCD forming part of the charger equipment itself. Testing verifies trip times at rated residual current (30mA) and at five times rated current. Regulation 722.531.3 requires an RCD with a maximum 30mA that disconnects all live conductors, including the neutral, single-pole RCBOs won’t work for EV circuits.
Functional testing proves the charger operates correctly: power-up sequence, vehicle communication, smart features (app connectivity, scheduling), emergency stop, LED indicators, and cable lock mechanisms.
Load testing runs the charger at maximum output (typically 7.4kW for domestic) for 30-60 minutes, monitoring for overheating, within-limits voltage drop, and stable protective devices.
Documentation and compliance forms
The EIC confirms electrical work has been designed, built, inspected, and tested according to BS 7671, so your installer should not leave without issuing it. The certificate contains installation details (address, date, installer), design details (circuit characteristics, cable types, protective devices), test results with actual measurements, and any departures from BS 7671.
Installers have 30 days to file the EIC with your local authority; without it, authorities could request work be redone, and you may receive a penalty fine.
Notifiable work must be reported to the local building control body (BCB) unless completed by someone registered on the competent person scheme who can provide a compliance certificate. Competent person scheme members (NICEIC, NAPIT, ELECSA, Stroma, BSI) can self-certify and notify directly. Part P ensures all electrical installations in residential settings meet specific safety standards outlined in UK Building Regulations.
Minimum documentation includes EIC and Building Regulations Certificate of Compliance. Comprehensive packages include: Risk Assessment, Method Statement, ENA Application Form, DNO confirmation email, EIC, Building regulations compliance certificate, EVSE Commissioning sheet, Manufacturer’s Manual, and Letter of findings and recommendations.
Distribution Network Operators need notification for chargers above 3.5kW, properties with solar/battery storage, and multiple chargers. DNO confirmation should be provided to verify proper procedure was followed.
Register your charger with the manufacturer immediately. Warranty claims require proof of purchase, installation date, installer details, and the serial number. Some manufacturers void warranties if installation wasn’t by approved contractors.
Store digital and physical copies of all documentation. You’ll need them for insurance claims, property sales, future electrical work, warranty claims, and local authority requests.
Visual checks and insulation resistance tests
Visual inspection identifies defects before energising circuits. Inspectors verify appropriate cable type, outdoor installations require weatherproof cabling and IP-rated fittings. Standard twin and earth cable outdoors fails immediately; only armored (SWA) or UV-resistant cable works.
Cable support prevents mechanical damage. BS 7671 specifies maximum spacing between clips (typically 400mm for horizontal flat cable runs). Protection from damage uses conduit or armouring where cables cross traffic areas. Underground cables need proper burial depth with warning tape. Minimum burial depths vary by location type—domestic, on-street, commercial, or industrial premises each have specific requirements.
Correct routing follows prescribed zones (vertical/horizontal within 150mm of corners, ceiling, or floor). Diagonal runs need mechanical protection. Appropriate terminations use correct terminals with proper torque. Overtightening crushes conductors; undertightening creates high-resistance joints, causing overheating.
Section 9 of the Fifth Edition IET Code includes additional guidance for inspection and testing procedures. Insulation resistance testing applies 500V DC to stress-test insulation. Minimum acceptable readings: 0.25 megohms for SELV circuits, 1.0 megohm for circuits up to 500V. Lower readings indicate water ingress, cable damage, or manufacturing defects requiring investigation.
Common failures: insufficient cable size for load, missing/incorrect RCD protection, poor terminations with exposed conductors, inadequate earthing, non-IP-rated equipment outdoors, incorrect circuit labelling, missing isolation devices, cables in unsafe zones, and inadequate mechanical protection.
Improved guidance specifies photo evidence needed for grant claims. Photos document: charger installed and labelled, consumer unit with new breaker, cable routing, earthing connections, testing equipment readings, and DNO meter position.
Certification and client handover
Professional installations include EIC, Building Regulations Certificate, DNO confirmation, and additional documentation as needed. Review each certificate for the correct property address, your name spelled correctly, accurate installation date, complete test results, installer signature and credentials, and scheme membership details. Errors invalidate certificates—request corrections before the installer leaves.
Installers should be members of a recognised competent person scheme; you can ask which scheme they’re on and double-check credentials online. Verify current registration status, scope covering EV work, and adequate insurance (typically £2 million public liability, £250,000 professional indemnity).
The installer demonstrates: plug-in and charging start procedures, app installation and setup, setting charging schedules, understanding LED indicators, using emergency stop, cable management, and basic troubleshooting.
You receive the manufacturer’s user manual, quick-start guide, app instructions, emergency contacts, maintenance schedule, and warranty information. Most chargers need monthly visual inspection, cable inspection before each use, quarterly RCD test button check, and professional inspection every 3-5 years.
You can check Part P notification was completed by checking your council’s planning portal. Visit your local authority’s planning portal, search by property address, and verify EV charger installation appears in building control notifications. If missing after 30 days, contact your installer.
Inform your home insurance provider immediately. Some insurers require notification for electrical work, offer discounts for EV installations, or update property valuations.
The EIC includes recommendations for next inspection intervals. Typical intervals: 5-10 years for owner-occupied domestic, 5 years for rental properties, 3-5 years for commercial installations. Schedule inspections before expiry to maintain compliance.
Need certified EV charger installation in London? Diligent Electrical Contractors provides complete testing, certification, and handover documentation for every installation. We’re NICEIC registered and OZEV-approved. All work includes full certification packages and local authority notification. Contact us for professional, compliant installations.
