Where is my stopcock?

Your internal stopcock, also called a stop tap, is usually close to where the supply pipe enters the home. Start under the kitchen sink, then check a downstairs toilet, utility room, hall cupboard, garage or cellar. In a flat, ask the landlord, managing agent or building manager if it is not inside the dwelling.

WaterSafe says the stop tap is often under the kitchen sink, but its position depends on the service point. A home can also have valves in an airing cupboard or loft that isolate stored-water supplies; these are not necessarily the incoming mains stop tap.

The external stop tap is commonly near the property boundary under a small cover. A water meter is often in the same chamber. WaterSafe says the external valve belongs to the local water supplier and may require its permission to operate, so contact the supplier rather than treating it as an everyday control.

Once you find the internal valve, label it and keep access clear. Turn it gently to check that it moves, then restore it. If it will not move or does not shut off the water, do not force it: arrange a plumber before an emergency makes the fault urgent.

Confirm that it is the right valve before relying on it. Close it gently, open the kitchen cold tap and check that the flow stops after the small amount already in the pipe has drained. A stored-water outlet may continue for longer because a cistern still contains water. Restore the valve afterwards and check around it for any sign of a leak. Tell everyone in the home where it is, but do not cover it with fixed cupboards or stored belongings.

Sources

• How to turn off your water supply safely — WaterSafe, accessed 14 November 2026.
• What should I do if I find a leak? — WaterSafe, accessed 14 November 2026.

On Leatmere

Read how to find a leak and the stopcock and check the stop tap definition.