A dripping tap costs £50 to £150 across the UK, averaging around £100 including VAT. The range is that wide because "dripping tap" names a symptom, not a repair. Three different faults produce it, they cost different amounts, and you can usually work out which one you have before anybody quotes.
What it costs in London, by repair
Housekeep, which publishes London and non-London figures separately and states its VAT basis, prices the three common repairs including VAT:
- Washer or O-ring: £60 to £95 in London, £50 to £70 outside
- Cartridge: £80 to £130 in London, £60 to £110 outside
- Valve: £120 to £150 in London, £90 to £140 outside
The London premium runs about £10 to £30 depending on the repair, which is consistent with the roughly 20% gap the same source documents between London and the rest of the UK.
Note what the spread is not made of. It is not parts. The components in all three repairs are cheap, and almost every pound of every figure above is an attended hour, which the answer on why plumbers are so expensive in the UK sets out in full. What separates £60 from £150 is how far the plumber has to get into the tap.
Where the water appears tells you which repair it is
This is the diagnosis, and it takes thirty seconds with a dry cloth.
Dripping from the spout with the tap fully closed. The seal that shuts the flow off has failed. On a traditional tap that is a perished washer; on a mixer it is a worn ceramic cartridge. This is the commonest and cheapest case.
Water appearing around the base of the spout, or weeping from under a handle, when the tap is running. Nothing is wrong with the shut-off. An O-ring or a gland seal further into the body has gone, and on a monobloc mixer that often means reaching the valve assembly, the dearest of the three.
Water underneath the unit, in the cupboard, rather than on the tap. That is not a tap fault at all. It is a compression fitting, a flexible tail or an isolation valve, and it wants dealing with promptly because it is soaking a carcass you cannot see.
Establish which of those three you have before you ring anyone. It is the difference between describing a problem and describing a job.
The type of tap narrows it further
Count the turns. A traditional tap with separate hot and cold heads that rotate several times has rubber washers in it, and those washers perish. A quarter-turn tap or a single-lever mixer generally does not: it uses a ceramic cartridge, and there is no washer in it to change. That is why "just change the washer" is sometimes not an option at all, and why a plumber who asks what kind of tap it is before quoting is doing the right thing rather than stalling.
While you are looking, note the brand if it is stamped anywhere, and whether the tap is a two-hole set or a single monobloc. On mixers the cartridge is often specific to the manufacturer, and a plumber who knows which one to bring finishes on the first visit.
Timing changes the number more than the tap does
Housekeep puts the uplift for an evening, weekend or emergency tap job at £40 to £60. That is a single source, so treat it as an indication. Checkatrade's position is broader and rests on better sourcing: out-of-hours work can run to twice the normal hourly rate, plus a call-out charge.
A dripping tap is almost never an emergency. It is loud, it is annoying, and it can wait until a weekday morning, which on these figures is the cheapest decision available.
Two things to do before anyone arrives
Find your stopcock and check it turns. Which? makes the cost argument directly: if the water cannot be shut off, the plumber may have to drain the whole system before repairing anything, which takes time and often means higher charges. Turn it slowly, clockwise, without forcing it. Older brass spindles seize with limescale and snap cleanly when twisted hard, turning a modest repair into a much larger one.
Then bundle. If a second tap is stiff or a cistern is slow, mention it when you book. The travel and the call-out are being paid for regardless, and the second job costs little more than the labour it takes.
A drip is a symptom with three prices attached, and the free part of the job is working out which one you are buying.