What counts as minor works?
Minor works means additions or alterations to an existing electrical installation where no new circuit is being created. Examples that require a Minor Works Certificate include:
- •Adding a socket outlet to an existing ring or radial circuit
- •Installing an additional light fitting on an existing circuit
- •Running a fused spur from an existing socket
- •Replacing a like-for-like switch or socket (non-notifiable under Part P)
- •Moving an existing socket or light switch
When you need an EIC instead
If you're installing a new circuit — a dedicated circuit for an electric shower, a new ring main, a cooker circuit — you need a full Electrical Installation Certificate (EIC), not a Minor Works Certificate. The EIC requires three separate sign-off sections and full design, construction, and inspection declarations.
If you're inspecting an existing installation to report on its condition (not carrying out new work), you need an Electrical Installation Condition Report (EICR). A Minor Works Certificate is only for additions or alterations to existing circuits.
BS 7671 requirements
Minor Works Certificates are required under BS 7671:2018 Amendment 2 (the 18th Edition Wiring Regulations). Under Part P of the Building Regulations, domestic electrical work that is notifiable must either be self-certified through a competent persons scheme (NICEIC, NAPIT, Elecsa, etc.) or notified to Building Control.
Most minor works are non-notifiable, but the certificate is still required for your own records and your customer's protection. If you're a member of a scheme, keep copies as evidence of compliant work.
What goes on the certificate
A compliant Minor Works Certificate must include:
- •Installation details: address, circuit description, distribution board location
- •Description of the work completed in plain English
- •Confirmation the existing installation was assessed before work commenced
- •Test results: continuity of protective conductors, insulation resistance, polarity
- •Whether the existing installation is suitable for the addition
- •Declaration that the work complies with BS 7671
- •Electrician's name, qualification (e.g. City & Guilds 2382), and signature
- •Date of completion
- •Customer signature confirming receipt
Common mistakes to avoid
These errors are the ones most likely to cause problems if your work is ever inspected:
- •Not testing after the work: even a quick spur addition needs continuity and polarity confirmed and recorded
- •Using a Minor Works Certificate for a job that requires a full EIC
- •Not specifying which circuit the work was carried out on
- •Leaving test result sections blank — inspectors and insurers look for these
- •Failing to give the customer their copy within 30 days
Part P of the Building Regulations — notifiable work
Part P of the Building Regulations 2010 applies in England and Wales. It says certain domestic electrical work is 'notifiable' — Building Control must know about it. Notifiable work since the 2013 amendment covers installation of a new circuit, replacement of a consumer unit, and any addition or alteration in a 'special location' (bathrooms, outdoor work involving supply cables).
You satisfy Part P in one of three ways: by being a registered member of a competent person scheme (NICEIC, NAPIT, Stroma, Elecsa, ECA) and self-certifying; by notifying the work to Building Control in advance; or by using a Registered Third Party Certifier to inspect after the fact. Self-certification through a scheme is the cheapest route and the only practical one for most sole traders.
BS 7671:2018 Amendment 2:2022 — what's changed
The 18th Edition of the Wiring Regulations, Amendment 2, came into force on 28 March 2022 for all new designs, and 27 September 2022 for all new installations. The changes that matter most on Minor Works jobs:
- •AFDDs (Arc Fault Detection Devices) — now required for socket outlets up to 32A in HMOs, student accommodation, care homes, and buildings above 18m. Recommended elsewhere. Record AFDD presence or absence on the certificate.
- •RCD protection — Section 411.3.3 requires RCD protection on all socket outlets rated ≤32A and on cables buried in walls at less than 50mm depth
- •Surge Protection Devices (SPDs) — Section 443 now requires SPDs in most domestic installations unless a documented risk assessment allows otherwise
- •EV charging equipment — Section 722 introduces specific requirements for EV charging points, including earth electrode requirements for PME supplies
- •Fire safety — Section 422 requires designers to specify cables that limit flame propagation and fire loading
Scheme registration vs notifying Building Control
For sole-trader electricians who regularly do notifiable work, scheme membership is effectively mandatory. The current main schemes and their approximate 2026 annual costs:
- •NICEIC — around £550-700/year for Domestic Installer status
- •NAPIT — around £500-650/year with competent person status
- •Elecsa — around £450-550/year
- •Stroma — around £450-550/year
- •ECA — higher tier, typically £1,000+ for full membership
Special locations — bathrooms and outdoors
Section 701 of BS 7671 covers bathrooms and defines four zones (Zone 0, 1, 2, and outside zones). Each zone has specific rules on IP rating, RCD protection, and permitted equipment. A Minor Works job in a bathroom (moving a shaver socket, adding an extractor fan) is notifiable under Part P — self-cert through your scheme or it's non-compliant.
Section 705 covers outdoor installations. Running a cable from a consumer unit to a garden shed or outbuilding is notifiable — it crosses the boundary of the dwelling and requires specific consideration of underground cable protection, RCD protection, and (for metal outbuildings) supplementary bonding. Don't treat a shed feed as a casual Minor Works job.
Test values that matter in court
If an electrical fire or shock incident leads to investigation, the first thing an expert witness asks for is the test results. 'All tests passed' with no figures is often rejected. Record the actual figures:
- •Continuity of CPC — typical for a short spur: 0.10-0.30Ω (depending on cable length and cross-section)
- •Insulation resistance — minimum 1MΩ, typically 50+ MΩ on a healthy new spur. Record the actual figure at 500V DC
- •Polarity — confirmed (but make a note of the method: visual inspection, continuity test)
- •Earth fault loop impedance (Zs) — must be below the tabulated value for the protective device (e.g. 1.44Ω for a 32A Type B MCB in a TN-S system at 80% of nominal)
- •RCD trip time — must operate within 300ms at rated residual current, and within 40ms at 5× rated current (for 30mA RCDs)
Generating certificates quickly
Paper certificates are easy to fill in wrongly on site, and generic Word templates miss fields. TradeDoc AI generates a compliant Minor Works Certificate from your job details in minutes — including the test results section — and produces a PDF you can email to the customer before you pack up.
Your document vault stores every certificate automatically, so you have a searchable record if a customer queries the work months later.
