How to Price a Consumer Unit Replacement
A consumer unit change is a day’s work with a certificate at the end of it — price the board, the labour, the testing and the paperwork, and leave room for what the change reveals.
Consumer unit replacements look like a fixed job — swap old board for new — but the honest price is a build-up: the board and its devices, roughly a day’s labour, the testing and certification, making good, and a contingency for remedial work that only becomes visible once the old board is off the wall.
This guide walks through that cost build-up, explains why faults uncovered during a change legitimately add to the bill, and covers the notification and Part P side that a compliant change carries. The figures are indicative UK 2026 ranges — typical, not fixed, and subject to regional variation.
Key takeaways
- Price a CU change as a build-up: board + devices, about a day’s labour, testing, certificate and making good — then add margin.
- A modern dual-RCD or all-RCBO board with SPD costs materially more than a basic board; quote the specification, not "a board".
- Remedial work found once the old board is off (poor bonding, damaged cables, borrowed neutrals) legitimately adds cost.
- The job includes full testing and an Electrical Installation Certificate — that testing time is part of the price, not a freebie.
- A consumer unit change is notifiable under Part P; account for notification via your competent person scheme or building control.
1. The cost build-up
Start with materials. A consumer unit change is board plus protective devices, and the device choice dominates the cost — a basic dual-RCD board is one thing, a fully populated all-RCBO board with a surge protection device (SPD) is another entirely. Add tails, henley blocks or an isolator if fitting one, bonding conductors if you’re upgrading them, and sundries.
Then labour: a straightforward domestic change is broadly a day on site for one electrician, covering isolation, removing the old board, mounting and wiring the new one, and the full test and inspection at the end. Add certification time and making good. Finally overheads and margin, drawn from your day rate rather than guessed at.
Quote the specification
"A new board" means nothing until you say how many ways, RCD or RCBO protection, and whether an SPD is included. Spell out the specification in the quote so a like-for-like comparison with a cheaper rival is actually possible.
2. Why remedial work adds cost
You can’t certify a new consumer unit onto an installation you haven’t verified. Once the old board is off you may find undersized or missing main bonding, no earth at the origin, borrowed neutrals between circuits, damaged cable insulation, or circuits that won’t pass insulation resistance. None of that is optional to address — the certificate depends on it.
The fair way to handle this is to flag the risk in the quote. Price the change itself, then state that any pre-existing defects found during the work will be reported and quoted before you proceed. That protects you from absorbing hours of unexpected remedial work and protects the client from a surprise on the invoice.
3. Testing and certification
A consumer unit change is new work and gets an Electrical Installation Certificate, not a Minor Works Certificate. That means testing every circuit — continuity, insulation resistance, polarity, earth fault loop impedance and RCD operation — and recording the results on a schedule of test results. That testing is a real chunk of the day and belongs in the price.
Don’t treat the certificate as an afterthought. It’s the document that proves the installation is safe and the reason the job is worth what you charge. Building the test-and-certify time into the quote from the start stops it becoming unpaid evening admin.
Certify while you’re there
TradePlanr lets you record the schedule of test results and issue the Electrical Installation Certificate as a PDF on site, so the paperwork is finished with the job rather than chased up later.
4. Indicative price ranges
The table gives typical 2026 UK ranges. The spread within each row is driven mostly by board specification and by how much remedial work turns out to be needed — the same physical swap can sit at the bottom or top of its band depending on what the old installation was hiding.
Regional variation is significant: expect London and the South East to run above these figures and much of the country to sit within or below them. Use the table to sanity-check a quote you’ve built from your own costs, not as a headline price to advertise.
| Scenario | What’s involved | Indicative price |
|---|---|---|
| Straightforward like-for-like change | Basic board, no remedials, good access | £400–£600 |
| Standard change, modern board + SPD | All-RCBO board, SPD, minor making good | £550–£850 |
| Change with bonding upgrade | New main bonding to gas/water added | £650–£1,000 |
| Change with significant remedials | Faults found, additional circuits made safe | £900–£1,500+ |
5. Notification and Part P
Replacing a consumer unit is notifiable work under Part P of the Building Regulations in England and Wales. You either self-certify through membership of a competent person scheme (NICEIC, NAPIT and others) or, if you’re not a scheme member, notify building control in advance and pay their fee — which is slower and usually more expensive.
Whichever route applies, the cost of notification is part of the job and should be reflected in the price. Scheme members carry that cost within their annual fees; if you’re notifying building control per job, add it explicitly. Either way the client should end up with both the certificate and confirmation the work was notified.
Frequently asked questions
How long does a consumer unit change take?
A straightforward domestic change is broadly a day on site for one electrician, covering isolation, removal, fitting and wiring the new board, and the full test and inspection. Remedial work found once the old board is off can extend that, which is why any defects are usually quoted separately.
Why did the price go up once the electrician started?
Because faults hidden behind the old board — poor bonding, damaged cables, borrowed neutrals, circuits failing insulation resistance — often only become visible during the change, and they must be put right before the installation can be certified. A good quote warns of this up front.
Is a consumer unit change notifiable?
Yes. In England and Wales it’s notifiable under Part P of the Building Regulations. Scheme members (NICEIC, NAPIT etc.) self-certify; non-members must notify building control in advance and pay a fee. Either way the client should receive an Electrical Installation Certificate.
From guidance to action
Related guides
Consumer Unit Upgrades Explained
What a consumer unit change involves — assessing the existing installation, RCBO boards and paperwork.
Consumer Unit Regulations (BS 7671)
The regulations behind consumer units — non-combustible enclosures, RCD/SPD/AFDD provision and RCBO boards.
How to Price a Full Rewire (UK 2026)
Per-point vs day-rate pricing, what a full rewire includes, and how to build a rewire quote that holds its margin.
