How Much Does a Consumer Unit Replacement Cost in 2026?
A standard consumer unit replacement costs £350 to £600. The job takes 4 to 6 hours and must be done by a Part P registered electrician who will certify the work on completion.
£350–£500
Standard swap
£400–£600
With RCD upgrade
4–6 hours
Time taken
Most of the day
Power off
Prices updated April 2026 · Based on industry data and contractor submissions.
Replacing a consumer unit is notifiable work under Part P of the Building Regulations. It must be carried out by a Part P registered electrician who will self-certify and notify Building Control. You will receive an Electrical Installation Certificate on completion.
Consumer Unit Replacement Prices
Prices include the consumer unit, fitting, full circuit testing, and Part P certification.
| Type | Cost |
|---|---|
| Like-for-like replacement | £350 – £500 |
| Upgrade with RCD protection | £400 – £600 |
| Upgrade + new circuits | £500 – £800 |
| Full upgrade during rewire | Usually included |
Prices based on industry averages for 2026. Actual costs vary by location and complexity.
What Is a Consumer Unit?
A consumer unit is the modern name for what most people still call a fuse box. It is the grey or white box - usually near your front door or under the stairs - that controls all the electrical circuits in your home.
MCBs (Miniature Circuit Breakers)
These are the individual switches inside the unit - one for each circuit (lights, sockets, cooker, shower, etc.). When a circuit is overloaded or develops a fault, the MCB trips and cuts the power to that circuit only, rather than the whole house. Unlike old fuse wire, you just flip the switch back on once the fault is cleared.
RCDs (Residual Current Devices)
RCDs are the safety devices that protect you from electric shock. They monitor the current flowing through a circuit and cut the power within milliseconds if they detect current leaking where it should not be - for example, through a person. Modern consumer units split circuits across two or more RCDs, so a fault on one group does not trip everything. Current regulations require RCD protection on virtually all circuits.
SPDs (Surge Protection Devices)
Since the 18th Edition wiring regulations (2018), surge protection is required in most new or replacement consumer units. SPDs protect your appliances and electronics from voltage spikes caused by lightning strikes or switching surges on the mains supply. Given how much electronic equipment most households own now, this is a genuinely useful addition.
Signs You Need a Consumer Unit Replacement
Not every old fuse board needs replacing immediately, but these are the signs that yours is overdue for an upgrade.
| Sign | Action |
|---|---|
| Old-style rewirable fuses (fuse wire visible) | Upgrade recommended |
| No RCD protection fitted | Upgrade recommended |
| Fuses or breakers tripping frequently | Get it inspected |
| Scorch marks or burning smell from the unit | Urgent - call an electrician |
| Insurer has flagged your fuse board | Upgrade to maintain cover |
| You are adding a new circuit (EV charger, hot tub, extension) | Upgrade likely needed |
What Happens During a Consumer Unit Replacement?
The job is straightforward but takes most of a working day. Here is what to expect.
- 1
Initial inspection and testing
The electrician tests all existing circuits to check their condition. This is important because replacing the consumer unit is pointless if the wiring itself has faults. If they find problems, they will flag them - this can add to the cost, but it is better to know now than to fit a new board on dodgy wiring.
- 2
Power off and old unit removed
The electricity supply is isolated at the main switch or meter. The old consumer unit is disconnected and removed. This is the point where your power goes off and stays off until the new unit is wired in and tested.
- 3
New unit fitted and wired
The new consumer unit is mounted (usually in the same position) and all circuits are connected. The electrician will configure the MCBs and RCDs to match your household circuits, splitting them across RCD groups so that a fault on one circuit does not trip everything.
- 4
Testing and certification
Every circuit is tested to confirm it works correctly and safely with the new unit. The electrician issues an Electrical Installation Certificate (EIC) and notifies Building Control under Part P. Your power is back on - job done.
Do You Need Building Control Sign-Off?
Yes - but your electrician handles it
Replacing a consumer unit is classified as notifiable work under Part P of the Building Regulations. That sounds more complicated than it is. If you use a Part P registered electrician - and you should - they will self-certify the work and notify your local authority on your behalf. You do not need to fill in any forms or arrange any inspections. Within a few weeks of the work, you will receive a Building Regulations Compliance Certificate through the post.
What if the electrician is not Part P registered?
You will need to apply to your local Building Control department before the work starts. They will charge £200–£400 for a Building Notice, and an inspector will need to visit to check the work. This adds cost, time, and hassle. There is really no good reason to use a non-registered electrician for this job when registered ones are widely available.
Why the certificate matters
When you sell your home, the buyer's solicitor will ask for evidence that any electrical work was done to Building Regulations. Without the proper certificates, you may face delays, need to pay for a retrospective EICR, or accept a price reduction. Keep your Electrical Installation Certificate and Building Regulations Compliance Certificate with your property deeds.
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Get Free QuotesHow to Get Your Consumer Unit Replacement for Less
A consumer unit replacement is not hugely expensive in the grand scheme of home improvements, but there are still ways to keep the cost down.
Get three quotes and compare like for like
Prices for a consumer unit replacement vary more than you might expect. We have seen quotes range from £300 to £700 for the same job. Make sure each quote specifies the brand and type of consumer unit, the number of ways, and whether testing and Part P certification are included.
Bundle it with other electrical work
If you also need extra sockets, new lighting, or an EV charger circuit, getting it all done at the same time saves on labour. The electrician is already there and the power is already off - adding a circuit or two while the board is open costs far less than booking a separate visit.
Check your insurance first
Some insurers offer a small premium reduction when you upgrade to a modern consumer unit with full RCD protection. It will not pay for the whole job, but it can offset a chunk of the cost over the following years. Ring your insurer before the work and ask.
Useful resources
- NICEIC — Check your electrician is a registered competent person
- Building Regulations Part P — Legal requirements for electrical work in homes
- IET Wiring Regulations — The technical standard for UK electrical installations
Frequently Asked Questions
How much does it cost to replace a consumer unit?
A standard consumer unit replacement costs between £350 and £600, including the unit itself, fitting, testing, and Part P certification. If you need additional circuits adding at the same time (for an EV charger or new cooker, for example), expect to pay £500–£800.
Do I need a Part P electrician to replace a consumer unit?
Yes. Replacing a consumer unit is notifiable work under Part P of the Building Regulations. It must be done by a Part P registered electrician who will self-certify the work and notify Building Control. If you use someone who is not Part P registered, you will need to apply to Building Control separately, which costs £200–£400 extra and requires an inspector to visit.
How long does a consumer unit replacement take?
A straightforward like-for-like replacement takes 4 to 6 hours. Your power will be off for most of that time. If the electrician finds issues with the existing wiring during testing - which is not uncommon in older houses - it can take longer and cost more. A good electrician will warn you about this possibility upfront.
What is the difference between a consumer unit and a fuse box?
They do the same job - controlling and protecting all the electrical circuits in your home. A fuse box is the older term, used when the unit contained rewirable fuses. A consumer unit is the modern equivalent, fitted with MCBs (miniature circuit breakers) that trip a switch instead of blowing a fuse wire, plus RCDs (residual current devices) that cut the power instantly if they detect a fault that could cause electric shock.
Can my home insurance be affected by an old fuse box?
Yes. Some insurers will not cover electrical damage or fire if your consumer unit does not meet current standards. Others will insure you but charge a higher premium. If you have an old fuse box with rewirable fuses and no RCD protection, it is worth checking your policy wording. Upgrading to a modern consumer unit can sometimes reduce your insurance premium enough to offset part of the cost.
Written by James Carter, Less.co.uk energy specialist
Last updated: · Pricing based on industry data and verified contractor submissions · Methodology