What is BS 7671?
BS 7671, the IET Wiring Regulations, sets the requirements for electrical installations in the UK. The current edition is the 18th Edition (BS 7671:2018), which has been updated by a series of amendments. All Synergy Electrical installations are designed, installed, tested and certified to the current version.
The latest update: Amendment 4:2026
BS 7671:2018+A4:2026 is now the current version of the regulations. The previous version (incorporating Amendments 2 and 3) was withdrawn on 15 October 2026. Headline changes include:
- A new chapter covering stationary secondary batteries — highly relevant if you're considering battery storage
- New requirements for earthing and bonding of ICT equipment
- A new section on Power over Ethernet
- A major revision of the section on medical locations
- Incorporation of Amendment 3:2024, and further alignment with European and international standards
Key protections in the 18th Edition
RCD protection
Socket-outlets rated up to 32A generally require 30mA RCD protection, as do circuits supplying lighting in domestic premises. RCDs disconnect the supply very quickly if current leaks to earth, protecting against electric shock.
Surge protection
Surge protective devices (SPDs) protect against transient over-voltages, for example from lightning or switching on the network. The regulations require surge protection where the consequences of over-voltage could be serious, with a risk assessment approach in other situations.
Arc fault detection
Arc fault detection devices (AFDDs) detect dangerous arcing in cables and connections that can start fires. They're recommended in certain situations, and we can advise on whether they're appropriate for your property.
Fire-resistant cable supports
Wiring systems must be supported so they won't collapse prematurely in a fire — protecting occupants and firefighters.
Consumer units
Domestic consumer units must be in non-combustible enclosures, and components must be those declared suitable by the manufacturer.
Electric vehicle charging
Dedicated requirements cover EV charging installations, including the type of RCD protection and earthing arrangements.
What this means for you
Your existing installation doesn't automatically become unsafe when the regulations change — but new work must meet the current version, and periodic inspections compare your installation against it. An EICR will tell you how your electrics measure up.
This page is a plain-English summary. For exact requirements, refer to the official BS 7671 published by the IET and BSI.