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DIN rail consumer unit

Updated: October 2026

A short rail in the basket looks like a way to add a breaker, and it is the wrong object for that job. A DIN rail consumer unit alteration means the home board: a new circuit, a replacement unit, or work in a special location. The eight amazon.co.uk packs in this comparison are 100 mm to 300 mm slotted offcuts. They are not a consumer unit, and a higher star rating does not change that. The rows themselves are on the [DIN rail comparison](/hub/electrical-equipment/din-rail). The rules below are Approved Document P, GOV.UK and the IET's note on Scotland, not a fitting guide. A qualifying purchase can earn us a commission at no extra cost to you.

A short rail in the basket looks like a way to add a breaker, and it is the wrong object for that job.

Our top picks

Bigxin Bigxin 8-piece 300 mm rail

Best overall

Bigxin Bigxin 8-piece 300 mm rail
8.4/10about £10.99
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Finehenchi Finehenchi 4-piece 200 mm steel rail

Rank 2

Finehenchi Finehenchi 4-piece 200 mm steel rail
7.4/10about £5.79
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HUATEEN HUATEEN 6-piece 200 mm rail

Rank 3

HUATEEN HUATEEN 6-piece 200 mm rail
8.8/10about £6.99
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On this page
  1. 1.A rail pack is not a consumer-unit alteration
  2. 2.What is notifiable in England and Wales
  3. 3.Scotland is not Part P
  4. 4.What you can still do with a rail

A rail pack is not a consumer-unit alteration

The kept packs cost £4.79 to £10.99. They are slotted pieces with no BS, EN or IEC number on the listing. Finehenchi shows a CE tick, and that tick is not UKCA and not BS 7671. None of them is sold as a fuseboard, a busbar or a protective earth. Screwing one into the existing consumer unit to add a way is still an alteration of the board. A pack at £4.79 and a pack with a thousand reviews are the same kind of object: a mounting rail for a separate enclosure. Isolating the incoming supply is a matter for the distribution network operator when no suitable isolator exists. The incoming cut-out is not yours to pull.

What is notifiable in England and Wales

Approved Document P sets out the electrical safety requirement for dwellings in England. The notifiable cases in regulation 12(6A) of the Building Regulations are a new circuit, the replacement of a consumer unit, and an addition or alteration in a special location. You notify that work unless an installer on a competent-person scheme does it. A special location, in that document, is a room containing a bath or shower, in the defined zone, or a room containing a swimming pool or a sauna heater. The route that keeps you inside the rules in England and Wales is a registered competent person. You should come away with an electrical installation certificate and a Building Regulations compliance certificate.
Bigxin Bigxin 8-piece 300 mm rail

Testsieger

Bigxin Bigxin 8-piece 300 mm rail
8.4/10about £10.99
View offer

Scotland is not Part P

Part P is the England and Wales building-regulation label. The IET's page on Scotland and Northern Ireland says the England and Wales self-certification schemes do not apply to work in Scotland. If you are in Scotland, you still do not open the home board with one of these packs. Scottish building standards and BS 7671 still have to be met. In Scotland the Part P scheme sentence does not apply, and the board is still an electrician's job.

What you can still do with a rail

A wired doorbell transformer in its own enclosure, or a small control box that is separate from the consumer unit, can use one short rail. That is the job the 100 mm to 300 mm packs were kept for. The enclosure has to be proved dead before you drill or clip, and the sequence for that is how to mount a DIN rail. If the design earths through the rail, stop and read aluminium versus steel DIN rail. None of these packs is a PE or PEN bar.

Common questions

Can I screw one of these rails into my consumer unit to add a breaker?
No. The eight packs are short slotted rails with no BS, EN or IEC number. Adding a breaker means altering the board, and in England and Wales a new circuit or a consumer-unit replacement is notifiable. The rail's price and star rating do not make it a board component. Arrange a registered competent person rather than a different ASIN.
Is replacing a consumer unit notifiable where I live?
In England and Wales, yes. Approved Document P and GOV.UK list replacement of a fuse box or consumer unit, and a new circuit, as notifiable work unless a competent-person-scheme installer does it and notifies for you. You should receive an electrical installation certificate and a Building Regulations compliance certificate. In Scotland the Part P schemes do not apply, and the work is still not a rail-pack job.
What is a special location for Part P?
Approved Document P treats a special location as the zone around a bath or shower, and a room with a swimming pool or a sauna heater. Addition or alteration there is notifiable in England and Wales, alongside a new circuit and a consumer-unit replacement. A hallway cupboard that is not one of those locations can still be the consumer unit itself, and replacing that unit is notifiable on its own.
Does Part P apply in Scotland?
The England and Wales self-certification schemes do not apply to work in Scotland. That is the IET's statement, and it is why this page does not say Part P covers the UK. Scottish building standards and BS 7671 still apply. You still want an electrician for the board. This page does not invent a Scottish warrant list.
What certificates should I expect in England and Wales?
An electrical installation certificate for the work, and a Building Regulations compliance certificate from the competent-person route. The scheme is how notification is done without you filing the building notice yourself. A CE tick on Finehenchi, or RoHS on another title, is not either document, and it is not UKCA or BS 7671.
Is a doorbell transformer in its own box the same job?
No. One short rail in a separate enclosure for a wired doorbell transformer is the adjacent job these packs can serve. It is not an alteration of the consumer unit. Prove that enclosure dead, and follow the mounting page. The moment the transformer feed is a new circuit from the board, you are back in notifiable work in England and Wales.

Related pages

DIN rail buying guide

DIN rail

Aluminium vs steel DIN rail: dry clip or earth path

Best DIN rail: which short pack the UK notes support

How to mount a DIN rail in a separate dead enclosure

Sources

Public UK sources from the research digest. Shelf prices and star lines are the amazon.co.uk figures in the display file. Listings do not show BS EN 60715, UKCA or BS 7671 compliance.

  1. RS DIN rails guide (retrieved 22 October 2026)
  2. Weidmüller UK: DIN rails and mounting rails (retrieved 22 October 2026)
  3. Weidmüller brochure: DIN rails and electrical busbars (retrieved 22 October 2026)
  4. Techna DIN rail datasheet (retrieved 22 October 2026)
  5. IEC 60715:2017 (retrieved 22 October 2026)
  6. GOV.UK: Approved Document P (retrieved 22 October 2026)
  7. Electricity at Work Regulations 1989 (retrieved 22 October 2026)
  8. HSE: Electricity at Work Regulations 1989, HSR25 (retrieved 22 October 2026)