Part P & notifiable work — who must sign it off

The short answer

If your V2L home-backup plan adds a dedicated inlet circuit, a changeover or transfer switch, or a new or replacement consumer unit, then in England that work is notifiable under the Building Regulations. 'Notifiable' does not mean you ask permission first and then wire it yourself — it means the work must be designed, installed and tested by a competent person and then formally signed off through one of three routes. The car maker does not sanction back-feeding fixed wiring from a V2L outlet, and the contested floating-V2L-on-PME earthing must be designed and proven by test by a competent person — Part P is the legal layer that makes that non-negotiable.

What 'notifiable' actually means

Approved Document P (the government's practical guidance on meeting Part P) splits fixed electrical work in dwellings into work that is *notifiable* and minor work that is not. Notifiable work has to be checked — either by a building control body before and after, or self-certified by a registered competent person who is authorised to confirm it meets the Building Regulations. The 2013 edition narrowed the range of notifiable work and introduced the registered third-party certifier option, but the headline triggers — new circuits and consumer units — were kept.

Why a V2L changeover is normally notifiable

A V2L home-backup scheme is not a plug-in appliance. To switch a small essential board between the grid and the car you add fixed wiring: a dedicated inlet, an interlocked contactor or transfer changeover, and usually an alteration to the consumer unit or a new sub-board. Each of those is the sort of work Reg 12(6A) lists as notifiable. Treat the whole arrangement as notifiable unless a competent person confirms, for the specific job, that it genuinely falls outside the notifiable list.

• A dedicated V2L inlet circuit — a new circuit, normally notifiable.
• A changeover or transfer switch feeding an essential board — fixed wiring added to the installation.
• A new or replacement consumer unit / sub-board — explicitly notifiable under Reg 12(6A).
• Anything passing through a special location — stays notifiable (see below).

Who may sign it off (England)

In England there are three lawful routes to demonstrate that notifiable work complies. Which one you use is a matter of how the work is organised, not of whether it must be done by a competent person — that part is fixed.

1. Competent-person self-certification — an electrician registered with a scheme such as NICEIC or NAPIT carries out the work and self-certifies that it meets the Building Regulations, notifying their scheme.
2. Building control — you notify the local authority building control body, which inspects and signs the work off.
3. Registered third-party certifier — in England, a registered third-party can certify work done by someone who is not themselves scheme-registered.

Part P is England-specific — the devolved picture

This is the trap in any UK-wide guidance. 'Part P' and Approved Document P are the England regime. The other three nations regulate domestic electrical safety differently, so the 'is it notifiable / who signs it off' answer changes once you cross a border. The underlying technical standard — BS 7671 — is common across the UK; the *administrative* duty is not.

• England — Part P / Approved Document P (2013 edition): the notifiable / non-notifiable split described above.
• Wales — operates its own Part P / Approved Document P regime (devolved in 2011); later England-only amendments mean the live Welsh AD P text can differ.
• Scotland — the Building (Scotland) Act 2003 and the Building Standards system (standards 4.5 and 4.6, satisfied via BS 7671): a building-warrant model with no notifiable/non-notifiable Part P split.
• Northern Ireland — no Part P equivalent and no dedicated electrical-safety Technical Booklet; electrical safety sits under the Building Regulations (NI) framework, with BS 7671 used as the accepted technical standard. Technical Booklet E is fire safety, not electrical safety.

Part P vs BS 7671 — two different layers

Part P and BS 7671 are often spoken of together, but they do different jobs. Approved Document P is the legal/administrative layer: it decides whether work is notifiable and who may certify it. BS 7671 is the technical layer: it decides how the installation must be designed, earthed, protected and tested. Approved Document P treats BS 7671 as the recognised way to achieve electrical safety, so it points to it rather than restating any wiring detail. A V2L page cites Part P for the notification duty and BS 7671 for the design — the PME/open-PEN earthing, the changeover, the RCD selection.

What this means for your V2L project

Treat a V2L home-backup changeover as notifiable from the start, and plan for a competent person to design, install, test and certify it. That gives you the Electrical Installation Certificate (proving it was tested to BS 7671) and the Building Regulations compliance certificate (proving the notifiable-work duty was met). Both matter — for safety, for selling the property later, and for insurance.