Definition & terminology

Fuse board vs consumer unit — what's the difference?

Same thing, different names — and what's changed inside the box.

The short answer

A fuse board, fuse box and consumer unit are the same thing — the central panel that takes your incoming supply and splits it into the separate circuits around your home, with protection on each one. 'Fuse box' is the older term from the days of rewireable fuses; 'consumer unit' is the modern name for a board fitted with circuit breakers. The key difference is what's inside: an old fuse box uses rewireable fuse wire with no residual-current protection, while a modern consumer unit uses MCBs (which switch off on overload), RCDs (which cut the power fast if they detect a leakage that could cause a shock), and increasingly RCBOs (a combined device that does both, per circuit). The job a board does hasn't changed; the safety devices inside it have.

People use 'fuse board', 'fuse box' and 'consumer unit' interchangeably, and that's fine — they refer to the same panel. What matters is what's inside it, because that's what determines the protection your home has.

The terms and parts

Same job, different generations

What the devices inside do

The difference that matters is the protective devices. An MCB (miniature circuit breaker) switches a circuit off on overload or short circuit and can be reset. An RCD (residual current device) monitors for current leaking to earth — the situation behind most electric shocks — and disconnects in a fraction of a second. An RCBO combines both functions in a single device fitted per circuit, so one fault isolates just that circuit. A modern board uses a mix of these; an old rewireable fuse box has none of them.

Why it matters: the label on the box is just a name, but the devices inside set the level of protection. If yours still has rewireable fuses, that points to an older installation that may lack residual-current protection — see the page on when a board needs replacing.

Not sure what you've got?

We'll match you with a vetted, registered electrician who can look at your board, tell you whether it's a modern consumer unit or an older fuse box, and explain honestly what's protected.

Free to be matched. You agree any price with the electrician directly.

Frequently asked questions

Is a fuse board the same as a consumer unit?

Yes. Fuse board, fuse box and consumer unit all refer to the same central panel that splits your supply into circuits. 'Consumer unit' is the modern term used in the wiring regulations; 'fuse box' is the older name.

What's the difference between an RCD and an RCBO?

An RCD cuts the power if it detects current leaking to earth, protecting against shocks, and typically covers several circuits. An RCBO combines that protection with an overload breaker (MCB) in one device per circuit, so a fault isolates just that circuit.

Do I still have a fuse box if I have rewireable fuses?

If your board uses rewireable fuse wire rather than switch-like circuit breakers, it is an older-style fuse box. That usually means it lacks the residual-current protection a modern consumer unit provides.

Sources & further reading

Figures on this page are typical UK ranges drawn from published sources and depend on your specific property and installation. They are guidance, not a quotation.