Running a business in London means dealing with electrical systems that are more demanding, more regulated, and more expensive to fix than anything in a typical house. Whether you are fitting out a new office, keeping a restaurant kitchen compliant, or managing a portfolio of rental commercial units, you need an electrician who understands commercial work — not someone who usually wires up loft conversions and is winging it on a three-phase board.
This guide covers what commercial electricians actually do, what the work costs in London in 2026, the regulations you need to be aware of, and how to pick the right contractor without learning the hard way.
What does a commercial electrician do?
A commercial electrician works on electrical systems in non-domestic premises — offices, shops, restaurants, warehouses, landlord common areas, and mixed-use buildings. The core difference from domestic work is not just scale. Commercial electrical systems are more complex, the regulatory requirements are stricter, and the consequences of getting it wrong are more serious.
Key differences from domestic electrical work
- Three-phase power — most commercial premises run on a three-phase supply rather than the single-phase supply found in homes. Incorrect balancing across phases causes overloading, tripped breakers, and in serious cases, fires.
- Higher loads — commercial kitchens, server rooms, air conditioning units, and industrial equipment draw significantly more power than domestic appliances. The wiring, distribution boards, and protective devices need to handle it.
- Fire alarm and emergency lighting integration — commercial buildings have legal requirements for fire detection and emergency lighting that go well beyond a domestic smoke alarm. Your electrician needs to understand how these systems tie into the main electrical installation.
- Compliance documentation — businesses face inspections from local authority building control, fire safety officers, landlords, and insurers. Every piece of commercial electrical work needs proper certification.
Types of commercial electrical work
Office fit-outs and refurbishments
This is the bread and butter of commercial electrical work in London. A typical office fit-out involves:
- Power and data cabling to workstations
- Dedicated circuits for server rooms and comms cabinets
- LED lighting design and installation
- Distribution board upgrades to handle the new layout
- Fire alarm and emergency lighting to meet Building Regulations
Most London offices are in older buildings where the existing electrical infrastructure was not designed for modern power demands. Adding 40 workstations to a building wired in the 1980s usually means upgrading the incoming supply and distribution, not just running some new cables.
Retail and hospitality
Shops, restaurants, cafes, and bars each have specific electrical requirements:
- Retail — display lighting, CCTV, alarm systems, EPoS tills, signage
- Restaurants and cafes — commercial kitchen circuits (often requiring dedicated 32A or 45A supplies), extraction fan wiring, under-counter refrigeration
- Pubs and bars — cellar cooling systems, glass washers, entertainment systems, outdoor lighting and heaters
Restaurant fit-outs in London are particularly demanding because commercial kitchen equipment draws enormous power. A combi oven alone can need a dedicated 32A supply on its own circuit.
Landlord compliance and common areas
If you own or manage a commercial building, you are responsible for the electrical safety of communal areas, shared services, and the incoming supply. This includes:
- EICR inspections — periodic testing of the fixed wiring installation, required every five years for most commercial premises. See our honest London EICR pricing guide for what this costs.
- Emergency lighting testing — monthly flick tests and annual full-duration discharge tests, documented and filed.
- PAT testing — any portable appliances you supply to tenants or common areas need regular testing. Our PAT testing guide for London businesses covers the requirements in detail.
- Fire alarm maintenance — weekly tests and quarterly professional inspections as a minimum.
Consumer unit and distribution board upgrades
Commercial consumer unit and distribution board upgrades are more involved than domestic ones. A commercial premises may have multiple distribution boards feeding different areas or floors, and the main switch panel can be significantly larger. Upgrading a commercial board often means coordinating a planned power shutdown with tenants, which requires careful scheduling.
How much does commercial electrical work cost in London?
Commercial electrical pricing varies significantly depending on the scope, but here are realistic London figures for 2026:
| Job | Typical cost range |
|---|---|
| Commercial EICR (small office / shop) | £250 – £450 |
| Commercial EICR (large premises / multi-floor) | £500 – £1,200+ |
| Office lighting upgrade (10-20 fittings, LED) | £800 – £2,000 |
| Full office fit-out electrics (small, up to 10 desks) | £2,500 – £5,000 |
| Full office fit-out electrics (medium, 20-50 desks) | £5,000 – £15,000 |
| Restaurant kitchen electrical fit-out | £3,000 – £8,000 |
| Commercial distribution board upgrade | £1,200 – £3,500 |
| Emergency lighting installation (per point) | £120 – £200 |
| Fire alarm installation (per zone, wired system) | £400 – £800 |
| PAT testing (50-100 items) | £100 – £200 |
| Three-phase supply upgrade (DNO application + installation) | £2,500 – £6,000+ |
These figures include labour and materials but exclude VAT. Prices at the higher end usually reflect older buildings where access is difficult, existing wiring needs replacing, or the incoming supply needs upgrading before the new work can proceed.
Watch out for: quotes that seem low often exclude the cost of the DNO (Distribution Network Operator) application, builder’s work for cable routes, or making good after the installation. Get a written scope of works before committing.
Regulations every business owner should know
BS 7671 (IET Wiring Regulations, 18th Edition)
This is the national standard for electrical installations in the UK. Every piece of commercial electrical work must comply with the current edition. The 18th Edition introduced stricter requirements for arc fault detection devices (AFDDs), surge protection, and energy efficiency measures that affect commercial installations.
Building Regulations Part P
Part P applies to electrical work in England and Wales. While it primarily targets dwellings, mixed-use buildings and HMOs (Houses in Multiple Occupation) fall within its scope. Notifiable work must be either carried out by a registered competent person (like an NICEIC-registered electrician) or inspected by local authority building control.
Fire safety regulations
The Regulatory Reform (Fire Safety) Order 2005 places the duty on the “responsible person” — usually the building owner, landlord, or employer — to ensure fire safety measures are adequate. This directly affects your electrical installation:
- Emergency lighting must comply with BS 5266
- Fire alarm systems must comply with BS 5839
- Electrical installations must not create a fire risk
Since the Grenfell inquiry, enforcement has tightened. Fire risk assessors are increasingly flagging outdated electrical installations, overloaded circuits, and missing emergency lighting as high-priority issues.
Electrical Safety Standards in the Private Rented Sector
If your commercial space is leased, your landlord must provide a valid EICR. If you are the landlord, you must ensure the installation is inspected at the intervals specified in the report, and no less frequently than every five years.
Why NICEIC accreditation matters for commercial work
NICEIC is the UK’s leading certification body for the electrical contracting industry. For commercial work specifically, it matters because:
- Competence is verified — NICEIC-registered contractors are assessed annually. Their work is inspected, their qualifications are checked, and their insurance is verified. This is not a badge you buy and forget about.
- Self-certification — NICEIC-registered electricians can self-certify notifiable work under Part P without involving building control. This saves you time and the cost of a separate building control application.
- Insurance and compliance — most commercial insurers and landlords require electrical work to be carried out by a contractor registered with a government-approved competent person scheme. NICEIC is the most widely recognised.
- Warranty protection — NICEIC Platinum Promise provides a six-year warranty backed by the scheme itself, not just the individual contractor. If the contractor goes out of business, the warranty still stands.
For any commercial work over and above a basic like-for-like replacement, using an unregistered electrician is a false economy. You will likely need to pay a registered electrician to inspect and certify the work afterwards anyway.
How to choose a commercial electrician in London
Check registration and insurance
At minimum, your commercial electrician should be:
- Registered with a competent person scheme (NICEIC, NAPIT, or ELECSA)
- Insured for commercial work — domestic insurance may not cover commercial premises
- Qualified to at least 18th Edition (BS 7671:2018 + Amendment 2)
Ask for proof. A reputable contractor will provide it without hesitation.
Look for relevant commercial experience
Not all electricians do commercial work regularly. The electrician who rewires houses may not be comfortable with three-phase distribution, commercial fire alarm systems, or coordinating with mechanical and HVAC contractors on a fit-out. Ask for examples of similar projects.
Get a written quote with a clear scope
A professional commercial electrician will carry out a site survey before quoting. The quote should itemise:
- Labour and materials separately
- Any allowances or provisional sums
- What is and is not included (making good, decoration, DNO costs)
- A realistic programme showing how long the work will take
- Any planned power shutdowns and their duration
Check reviews — but check the right ones
Online reviews matter, but for commercial work, look specifically for reviews from other businesses. A five-star review for changing a domestic light fitting tells you nothing about whether the contractor can handle a three-phase office fit-out.
F&A Electrical — commercial electrical services across London
F&A Electrical provides commercial electrical services across inner London, including offices, retail units, restaurants, and landlord-managed buildings. We are based in N15 South Tottenham and cover all inner London boroughs.
Why businesses choose us:
- NICEIC accredited and Part P registered — all work self-certified, no building control delays
- Fully insured to £5 million — adequate cover for commercial premises and public liability
- 237 Checkatrade reviews averaging 9.7/10 — verified, independent reviews from real customers
- Honest pricing — we quote what the job actually costs, explain what is included, and do not pad invoices with unnecessary extras
- Responsive — commercial downtime costs money. We understand that and schedule accordingly
We handle everything from single-circuit additions and emergency lighting installs through to full office fit-outs and commercial distribution board upgrades.
Get a quote for your commercial electrical work
If you need a commercial electrician in London, we are happy to carry out a free site survey and provide a written quote with no obligation.
Get in touch for a quote or call us on 07407 627542. We will visit your premises, assess the scope of work, and give you a straightforward price.