BS 7671 Amendment 4: the transition period ends on 15 October

Amendment 4 to BS 7671 was published on 15 April 2026. It could be applied straight away, and it came with a six-month transition period. That period ends on 15 October 2026, when the previous version is withdrawn.

What has changed

According to a technical piece by Kevin Sparrow of EAL in Professional Electrician, the amendment revises the sections covering:

• Medical locations
• Power over Ethernet (PoE)
• Information and communication technology equipment and systems
• Functional earthing and bonding
• Stationary secondary batteries
• Low voltage generating sets

It also clarifies a number of points that come up on ordinary domestic and commercial work: conductor identification, protection against premature collapse in a fire, buried cables, load curtailment, and how to choose RCD types when they are connected in series.

Battery storage gets its own attention

The section on stationary secondary batteries is the one most likely to touch domestic installers, given how many battery systems now go in alongside solar. The new requirements cover where a battery can be installed, particularly in dwellings, along with ventilation, identification and notices. They are written to line up with PAS 63100, the specification for electrical energy storage in homes.

Do you need to retrain?

No. Holders of the 18th Edition qualification are not required to sit it again. EAL has launched a new Wiring Regulations qualification with free teaching resources, and says many electricians are choosing to do it as continuing professional development. There are free webinars on Amendment 4 on EAL's YouTube channel, run with the IET.

Before 15 October

• Get hold of Amendment 4 and read the battery storage and RCD sections at the very least.
• If you design installations, check which version your open quotes and specifications refer to.
• If you fit batteries, compare your standard installation against PAS 63100.