Fuse box (consumer unit) replacement cost in 2026: what the price includes
In short: Replacing a fuse box (consumer unit) typically costs £450 to £700 in 2026 including the board, labour and the Electrical Installation Certificate, rising to £800 or more where the earthing and bonding need upgrading first. The job takes most of a day because every circuit must be tested and certified, not just reconnected.
Key points
- Budget £450 to £700 for a straight swap, £650 to £850 where bonding needs upgrading, plus VAT.
- Most of the day and most of the price is testing and certifying every circuit, not the swap itself.
- A modern board is expected to include surge protection (SPD); RCBO-per-circuit is the quality norm.
- Earthing and bonding get verified and corrected first; a new board is never energised onto failing earthing.
- It is notifiable work and must come with an EIC and Part P notification.
Replacing the fuse box is the most quoted job in domestic electrical work and the one where prices spread the widest. The board itself is a couple of hundred pounds. What the customer is actually buying is a day of methodical testing and a certificate that stands behind every circuit in the house, and that is where the price comes from.
Fuse box or consumer unit?
They are the same thing. "Fuse box" is what everyone says; "consumer unit" is the term BS 7671 uses. The old name comes from the rewirable fuses in boards fitted decades ago. A modern replacement uses circuit breakers, RCDs or RCBOs and usually surge protection, but the job people mean when they ask to replace the fuse box is a consumer unit change, and that is what this guide prices.
Typical prices in 2026
| Job | Typical range |
|---|---|
| Straight swap, modern earthing, up to 10 ways | £450 to £600 |
| Larger property or split-load with SPD | £550 to £700 |
| Swap plus main bonding upgrade | £650 to £850 |
| Swap where rewiring faults surface under test | quoted after investigation |
Plus VAT where the firm is registered. London and the South East run 15 to 25 percent above these numbers, as with EICR pricing.
Why the earthing moves the price
The regs are blunt on this: you do not connect a new consumer unit to an installation whose earthing and bonding you have not verified. If the main protective bonding to the water and gas services is missing, undersized at 6mm where 10mm is needed, or the earthing conductor itself is inadequate, that work happens first. It is not upselling; energising a new board onto bad earthing puts the installer's signature on someone else's defect.
What surfaces under test
Old boards hide problems that only appear when every circuit is dead-tested. Borrowed neutrals between lighting circuits, insulation resistance dragged down by a forgotten junction box, a ring final that is not a ring. On most houses these are an hour of tracing; occasionally they are the start of a bigger conversation. A fair quote says up front how surprises will be handled rather than absorbing them silently into a price that punishes honest houses.
The paperwork that should follow
A consumer unit change is new work, so it gets an Electrical Installation Certificate, not a condition report, with a schedule of test results listing every circuit's Zs, insulation resistance and RCD times. In England and Wales the job is notifiable under Part P, so it is either registered through the electrician's scheme or via building control. If a quote is cheap because no certificate is included, the job is incomplete and it will surface at the next safety certificate or house sale.
Questions worth asking any quote
Does the price include the certificate and Part P notification? Is an SPD included, as current regs expect on most domestic boards? What happens if the bonding needs upgrading? An electrician who answers those three without hesitation is quoting the whole job. One who cannot is quoting a board swap and leaving the rest to chance.
What goes into a modern board
Part of the price spread is specification. The cheapest quote and the dearest are often not the same product at all.
| Component | What it does | Effect on price |
|---|---|---|
| RCBOs (one per circuit) | Combined overload and RCD protection per circuit, so one fault does not down half the house | Dearer than dual-RCD, and the better install |
| Surge protection device (SPD) | Protects equipment from voltage surges; expected on new boards since Amendment 2 | Adds parts cost, normally included |
| Arc fault detection (AFDD) | Detects dangerous arcing; recommended for higher-risk premises | Optional on ordinary dwellings, priced per circuit |
| Main switch and enclosure | Non-combustible metal enclosure as standard since Amendment 3 | Baseline on any compliant board |
Earthing and bonding sizes, in plain numbers
The reason a board change sometimes turns into a bigger job is conductor sizes that were fine years ago and are not now. On a typical TN-C-S (PME) domestic supply, the figures an electrician checks are:
| Conductor | Typical minimum |
|---|---|
| Main protective bonding to water and gas (PME supply) | 10mm² |
| Main earthing conductor | 16mm² commonly, sized to the supply |
Find 6mm bonding where 10mm is now needed, or no bonding at all, and that gets corrected before the new board goes live. It is not an upsell; it is the part of the job that makes the rest of it legal to energise, which is why an honest quote raises it after a survey rather than discovering it on the day.
Common questions
Why does a consumer unit replacement take a whole day?
Because the regs treat it as new work on every circuit it feeds. Each circuit gets dead tests, insulation resistance, polarity and earth loop readings before it goes back on, and those results have to appear on the schedule of test results with the certificate. The physical swap is the quick part.
Do I need a certificate for a new consumer unit?
Yes. A consumer unit change requires an Electrical Installation Certificate with a schedule of test results for every circuit, and in England and Wales it is notifiable under Part P, so the work must be registered with building control or done by a registered electrician who self-certifies.
Can a consumer unit be replaced without upgrading the bonding?
No competent electrician will energise a new board onto earthing and bonding that fails inspection. If the main bonding to water and gas is missing or undersized, that gets fixed first, which is why surveys before quoting matter.
Do I need an SPD in a new consumer unit?
In most cases yes. Since Amendment 2 of BS 7671, surge protection is expected on new and replacement consumer units unless a specific documented risk assessment justifies leaving it out, and for a typical dwelling that justification rarely holds. A board quoted without an SPD is usually quoted cheap, not quoted right.
What is an RCBO board and why does it cost more?
An RCBO board gives each circuit its own combined overload and RCD protection, so a fault on one circuit does not take out half the house the way a shared dual-RCD board does. It costs more in parts but is the better install, and it is now the common specification on a quality consumer unit change.
Do I need AFDDs?
Arc fault detection devices are recommended by BS 7671 for certain higher-risk premises such as HMOs, care homes and similar. For an ordinary dwelling they are a recommendation rather than a blanket requirement, so they are an option your electrician should price and explain rather than a default.
Is a fuse box the same as a consumer unit?
Yes. Fuse box is the everyday name; consumer unit is the technical term in BS 7671. A modern board uses circuit breakers and RCDs rather than the rewirable fuses the old name describes, but people still call it the fuse box, and the replacement job and price are the same thing.
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