Blocked toilet: how to unblock it safely

Stop flushing. Then plunge.

The answer in 2 lines. Stop flushing, or the bowl may overflow. Wait for the water level to drop, then use a toilet plunger (one with a flange underneath). If that fails, try a toilet auger. If water also backs up in your shower, bath or a neighbour's home, the blockage is further down the drain: stop using water and call your landlord or a drainage engineer. If the blockage is in a shared sewer or outside your property, your water company usually deals with it for free.

The first 3 steps

Stop flushing and, if you can, turn off the small valve on the pipe feeding the cistern.
Protect the floor with old towels, and put on rubber gloves.
Check the other drains: if the shower or sink also backs up or gurgles, the blockage is in the shared drain.

Stop: danger

If you have poured in a chemical drain unblocker, don't plunge: splashes can burn your skin and eyes. If it gets in your eyes or is swallowed, rinse with water and call NHS 111, or 999 if someone is seriously unwell.
Macerator toilet (a box with a motor behind the toilet): switch it off at the plug or switch before doing anything, and don't use chemicals or force. Follow the manual or get a professional.

The steps, in order

Wait a little: a paper blockage sometimes softens on its own.
Hot water and washing-up liquid: a good squirt of washing-up liquid, then a bucket of hot tap water (never boiling), poured from a little height. Wait.
Toilet plunger (with a flange): seal it over the hole at the bottom of the bowl, under the water, and push and pull firmly.
Toilet auger: a flexible cable you push into the bowl while turning the handle, to break up or pull out the blockage.
Still blocked: call your landlord if you rent, or a drainage engineer.

What not to do

Flushing again "to see": the bowl overflows.
Pouring boiling water: it can crack the porcelain.
Using a small sink plunger: it won't seal at the bottom of the toilet.

Who deals with the drain?

Inside your property, a drain serving only your home is the owner's responsibility. If you rent, that is usually your landlord, unless you caused the blockage, for example by flushing wipes.
Shared sewers and drains, or drains outside your property boundary: since 2011, in England and Wales, these are the responsibility of your water and sewerage company, which will clear them free of charge.
If several homes are affected, or sewage comes up outside, call your water company.

Good to know

Only pee, poo and toilet paper go down the toilet. Wet wipes, even those labelled "flushable", cotton buds, sanitary products and nappies go in the bin.
If waste water has damaged your home or a neighbour's, contact your home insurer quickly.

In your city: your sewerage company

London: Thames Water.
Birmingham: Severn Trent.
Manchester and Liverpool: United Utilities.
Leeds and Sheffield: Yorkshire Water.
Newcastle: Northumbrian Water.
Bristol: Wessex Water for sewerage (your tap water comes from Bristol Water).
These are the companies for most of each city. Check your water bill: it shows which company handles your sewerage.

In Sheffield, Tom flushes and watches the water rise to the rim. He turns off the cistern valve, waits for the level to drop, then uses a flanged plunger. On the third try, the water rushes away. His son had flushed wipes: they now go in the bin.

A made-up story, for illustration.

Bobby

Sources, verification, confidence

Verified on 18 October 2026, for England. Confidence: high for the safe steps and the "3 Ps" rule (water companies, Water UK); high for the 2011 transfer of shared sewers (GOV.UK) and the sewerage company named for each city, though a few areas on city edges may differ: your bill is the final word; medium for the split between owner and water company, as the exact boundary depends on your property. We found no official statistics on blocked toilets. This guide describes common cases, not a diagnosis or legal advice.