Consumer unit upgrade cost: what a new fuse box should cost

What the job actually involves

Replacing a consumer unit is not a swap. Before the old board comes off the wall the electrician has to establish that the existing installation is safe to reconnect to a new one, because the moment the new board goes on, they are certifying it.

1. Pre-work testing — insulation resistance and continuity on every circuit, to confirm nothing will trip out the new RCDs the second the power goes back on.
2. Checking the earthing arrangement and main bonding — gas and water bonding to current sizes, and the main earthing conductor. This is where most of the unexpected extra cost lives.
3. Isolation — the supply is off while the work happens, typically for a couple of hours in the middle of the day.
4. Fitting the new board — mounting, terminating every circuit, labelling, and fitting any surge protection.
5. Full testing and certification — dead and live tests on every circuit, an Electrical Installation Certificate, a circuit chart on the board, and notification under Part P.

Total Skills puts the job at four to eight hours with the power off for two to four of them (last reviewed August 2026, checked 6 September 2026). MyJobQuote gives the same four-to-eight-hour window (last updated 4 August 2026, checked 6 September 2026). It is a day, in other words — which is why quotes that look like a couple of hours of labour should be questioned.

What drives the price

• Number of circuits. More circuits means a bigger board, more devices and more testing. This is the main driver.
• Board type. A dual RCD split-load board is cheaper; a full RCBO board costs more but means one fault takes out one circuit rather than half the house. Most electricians now recommend RCBOs, and the price difference is worth it.
• Pre-existing faults. If insulation resistance testing finds a borrowed neutral or a damp circuit, that has to be fixed before the new board goes on. It cannot be left.
• Earthing and bonding. Undersized or missing main bonding to gas and water is extremely common in older houses and is not optional.
• Meter tails and the position of the cut-out. Old or undersized tails need upgrading; some jobs need the supplier to attend.
• Where the board is. A board in an understairs cupboard behind fifteen years of stored coats takes longer than one at chest height in a hallway.
• Region. MyJobQuote puts a typical London job at £675 against £500 in the North West or North East (last updated 4 August 2026).

The extras that get added on the day

A good electrician will flag these on the survey. A less good one finds them after the old board is off the wall. Published ranges (Total Skills, last reviewed August 2026, and MyJobQuote, last updated 4 August 2026, both checked 6 September 2026):

• Earthing upgrades — £100 to £300 (Total Skills). MyJobQuote quotes earth bonding at £150 to £300.
• Supplementary bonding in bathrooms — £50 to £150.
• Meter tails upgrade — £100 to £200.
• Surge protection device (SPD) — £80 to £150.
• An additional circuit — £150 to £300 each.
• Fault repairs found on testing — MyJobQuote puts these at £100 to £500 or more.
• Moving the board a short distance — around £400. Moving it far enough to need the mains cable extending runs to £1,000 to £2,000 or more.
• An EICR at the same time — £120 to £300.

Part P: this job is notifiable

Replacing a consumer unit is one of the small number of jobs that must be notified under Part P of the Building Regulations in England. The IET lists the notifiable categories as installing a new circuit, replacing a consumer unit, and any addition or alteration to an existing circuit in a special location such as a bathroom (checked 6 September 2026).

• If your electrician is registered with a competent-person scheme, they self-certify the work and you receive a Building Regulations Compliance Certificate. The IET lists the recognised schemes as BESCA, Blue Flame Certification, NAPIT, OFTEC and Certsure, which trades as NICEIC and ELECSA.
• If they are not registered, the work must go through building control or a third-party certifier before it starts. Total Skills puts the building control route at £200 to £300 and stresses it must be notified before work begins (last reviewed March 2026, checked 6 September 2026).
• Wales retains broader notification requirements than England, so check locally if the property is in Wales.

The practical point for a homeowner: if the quote does not mention certification and notification, ask. Unnotified notifiable work is a problem that surfaces years later, when you sell.

What a fair quote looks like

1. It follows a survey, or at minimum a conversation about how many circuits you have and what the earthing arrangement is.
2. It names the board — make, number of ways, and whether it is dual RCD or full RCBO.
3. It separates the board and devices from the labour, so you can see what you are paying for.
4. It states what happens if pre-work testing finds a fault, with an hourly or day rate for remedials rather than a blank cheque.
5. It includes the Electrical Installation Certificate, the circuit chart and the Part P notification, and says so.
6. It says how long the power will be off.

Red flags

• A fixed price given over the phone with no questions about circuit count or earthing.
• No mention of testing before the new board goes on. Certifying an installation you have not tested is not acceptable practice.
• No Part P notification, or a vague answer about which scheme they belong to.
• A price that only makes sense as two hours of labour on a job that takes most of a day.
• Being told the bonding is fine without anyone looking at the gas and water pipework.
• No circuit chart left on the board, and no certificate afterwards.

What you should be given afterwards

• An Electrical Installation Certificate covering the new board, with the schedule of test results for every circuit.
• A Building Regulations Compliance Certificate for the Part P notification, which arrives from the scheme rather than the electrician.
• A circuit chart fixed inside or beside the board, naming what every device protects.
• A demonstration of the test button, and how often to press it.
• The manufacturer literature for the board, and details of any warranty.

Total Skills lists exactly this set — EIC, Building Regulations Compliance Certificate, circuit chart and an RCD test demonstration — as what should be included (last reviewed August 2026, checked 6 September 2026). Keep all of it: it is the paperwork a buyer's solicitor asks for.