Guide: Electrical
Consumer unit (fuse box) upgrade cost in the UK
A consumer unit, still widely called a fuse box, is the enclosure where every circuit in the house terminates. The current edition of the wiring regulations sets the minimum standard. Cost depends on the board type and circuit count, so get an itemised quote that includes certification rather than a bare hook price.
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Get matchedThe board types explained
- Standard split-load board (RCD plus MCBs): two RCDs cover groups of circuits. The cheaper option.
- RCBO-only board (per-circuit protection): a trip on one circuit takes out only that circuit. Cleaner on an EICR over the long term.
- Metal-clad board with surge protection (SPD): now recommended where the economic risk justifies it, and required in some scenarios.
- Three-phase board: for large detached and rural properties with a three-phase supply. The most involved upgrade.
When the upgrade is non-negotiable
- An old plastic board with no RCD: a C2 on every EICR.
- A re-wireable fuse board (the old plug-in carriers): a C2 minimum, often a C1.
- Adding an EV charger: usually triggers a surge-protection and load-management requirement.
- A heat pump install: needs a dedicated RCBO-protected circuit.
- A plastic board in a property you plan to let or remortgage, which insurers increasingly mark as material.
Why RCBO-only is usually worth the extra
On a split-load board, a single faulty appliance can trip an entire RCD and take half the house with it. On an RCBO-only board, only the affected circuit drops.
For households with freezers, home offices, or anyone working from home, that is a real reliability upgrade, not a paper specification.
What the all-in price should include
- The board itself (a recognised make such as Hager, MK, Wylex, Crabtree or Schneider).
- Every MCB or RCBO populated for the existing circuit count.
- A main earth and bonding upgrade if the existing is undersized.
- The EIC certificate issued at handover.
- Part P notification through the electrician competent-person scheme, or a Building Control fee where it is not.
What to watch for in quotes
The watch-out is "plus extras" wording. An honest quote includes the bonding upgrade as a contingency line, names the board make and model, and states the RCBO count. A vague "consumer unit replace" hook price often grows once the electrician is on site.
What it costs
- Standard or RCBO board
- Get a quote RCBO-only costs more than split-load but is cleaner on an EICR. Ask for both priced.
- Earth and bonding upgrade
- Quote as a contingency line An honest quote lists this separately rather than hiding it as an "extra".
- Certification
- EIC + Part P notification Included in a compliant job, not an add-on.
We do not publish a single fixed price; it depends on the board type, circuit count and whether bonding needs upgrading. Get an itemised quote that names the board and lists the RCBO count.
How to choose a vetted trade
- Use an electrician registered with a competent-person scheme (NICEIC, NAPIT, ELECSA or Stroma).
- Insist the quote names the board make and model and the RCBO or MCB count, and lists the bonding upgrade as a contingency line.
- Confirm the EIC is issued at handover and never pay the balance without it.
Frequently asked questions
Do I legally have to upgrade my fuse box?
There is no blanket law requiring an upgrade, but an old board with no RCD typically attracts a C2 on an EICR, which means it is potentially dangerous and improvement is recommended. Landlords must act on C1 and C2 codes. For owner-occupiers it is strongly advised on safety grounds.
Is an RCBO board worth the extra cost?
For most homes, yes. On an RCBO-only board a fault drops only the affected circuit rather than tripping half the house. That matters if you run a freezer, a home office or medical equipment. It also tends to read cleaner on a future EICR.
What should a fuse box quote include?
The named board, every MCB or RCBO for your circuit count, any earth and bonding upgrade, the EIC certificate, and Part P notification. Be wary of a low headline price with "plus extras" wording, which often grows once the electrician is on site.
Sources
Editor, Sorted Property
Oliver leads Sorted Property's editorial coverage of UK home services. He researches and writes the plain-English guides that help homeowners choose between installers and trades, drawing on the standards set by bodies such as MCS, TrustMark, the Energy Saving Trust and the Property Care Association, and is clear about what to check before any work starts.
Last reviewed: 11 June 2026