Amendment 4 (2026) to BS 7671:2018 IET Wiring Regulations.

Question

I assume it&rsquo;s now less than a year until the 4th Amendment is published, here on the IET website it says: 
 Amendment 4 is expected to be published in 2026, until that time electrical installers need to have a copy of Amendment 2 (2022) - the &lsquo;brown book&rsquo; and Amendment 3 (2024) (free PDF bolt-on) to be up to date. 
 https://electrical.theiet.org/bs-7671/updates-to-18th-edition/ 
 So, it is time to start planning ahead. 
 My first question is it a new book? There seems to be a lot of additional information and possibly changes as well. 
 My second question is, will there be an update qualification requiring a day on more in a training centre with an exam to be taken? 
 I have a couple of IET book markers somewhere with some information about this printed on them, but I&rsquo;m not sure where they are at this moment. 
 There is a third question, which is when the 19th Edition is being published, which presumably will require new books and an exam, but I assume that won&rsquo;t be published for at least two years?

gkenyon · Accepted Answer

Sparkingchip said: So, it is time to start planning ahead. 
 My first question is it a new book? There seems to be a lot of additional information and possibly changes as well. 
 There is no official information at the moment. However, lots of changes usually means the best approach is an updated 'book'. 
 Sparkingchip said: There is a third question, which is when the 19th Edition is being published, which presumably will require new books and an exam, but I assume that won’t be published for at least two years? 
 We don't know the answer to that question yet.

gkenyon · Answer

Sergio Fernandez said: Will BS7671 Amendment 4 address if a domestic dwelling smoke alarm IC (Inter Connect) conductor needs to be colour/identified and which colour should be used? 
 Why would it? It's a conductor of a system for which BS 7671 refers out to BS 5839 series in a number of places, including 110.1.3 (v). For example, BS 7671 tells you the identification for PE and FE conductors ... but it won't tell you whether the fire alarm loop earth is PE or FE: that's addressed by BS 5839-1:2025, see Clause 28.2. Similarly, BS 5839-6 already contains a provision that could be tightened up. In a similar manner, BS 7671 won't tell you which pin is connected to which core in an RJ45 plug or socket-outlet, or that different colours to Table 51 might be used in Machinery to BS EN 60204-1. 
 Sergio Fernandez said: Reasoning is that BROWN is for 230v nominal AC LIVE and as most/some people know the IC (Inter Connect) is 9V to 12V DC (Direct Current) during alarm operation or heartbeats. Thus maybe the colour for the IC should be RED. That being said that would be under normal operating conditions. Under fault conditions it is POSSIBLE that the IC may become live at 230V AC. 
 BUt it's a control/monitoring link (regardless of it being ELV, FELV or LV? BS 7671 permits a number of options at the bottom of Table 51. However, as above, you are referred to in Regulation 110.1.3 to another series of standards to decide what the function is and what the colour identification should be. See below - this is already covered in BS 5839-6. 
 Sergio Fernandez said: As a side note. In the UK, standard DC cable colour codes are as follows: Red is typically used for the positive (+) wire, and Black for the negative (-) wire thus RED for the IC makes sense to me. 
 No, for a DC power circuit, they are Red for L+, White for L-, and this has been printed as such in Table 51 since BS 7671:2018+A2:2022. 
 For AC or DC controls, see the bottom of Table 51 (BS 5839-6 already implies this by saying not the same colour as power conductors, see below) 
 Sergio Fernandez said: Caveat time 
 What if we have old cable in place, Red, yellow, blue? We would now have 2 reds. 
 What if we have old cable in place, Red, Black, Green/Yellow or bare? We would now have 2 reds. 
 This advice should be provided in BS 5839-6, which specifies the interlink. 
 BS 5839-6 already makes the following provision (my highlight): 
 16.4 Recommendations for wiring in Grade D systems The following recommendations should be met. 
 a) Cables used for the mains supply to smoke alarms and any heat alarms, and any interconnecting wiring between all smoke/heat alarms, should be suitable for domestic mains wiring. b) Conductors used for interconnection of smoke/heat alarms should be readily distinguishable from those supplying power (e.g. by colour coding). c) Wiring systems of any circuits in Grade D systems should conform to the general requirements of BS 7671.

Amendment 4 (2026) to BS 7671:2018 IET Wiring Regulations.

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