What happens if you put Leftover wet paint in the wrong bin?

Never pour paint down a drain or a gully; it goes to a watercourse and it is an offence in most places. Never put liquid paint in a wheelie bin — it bursts under compaction and the crew is entitled to refuse the whole load.

Where do Leftover wet paint go?

Household waste centre or a community paint reuse scheme. Liquid paint is not accepted in any household bin.

Household waste recycling centre

Liquid paint sloshes, leaks and coats everything it meets in a compactor, so collection crews reject it and most authorities ban it outright from kerbside bins. Usable emulsion is worth more than recycling: paint reuse networks, community projects and scout huts take part-tins of the same colour and pass them on. Solvent-based and gloss paints are a separate matter and count as hazardous waste, because the solvent is flammable and the older ones may carry heavy-metal pigments. Household waste centres vary widely in whether they take paint at all and whether they charge, which is worth checking before loading the car.

How to prepare it

Keep the lid on and the tin upright in a box or tray.
Offer usable tins to a paint reuse scheme before treating them as waste.
Keep water-based and solvent-based tins separate — they take different routes.

What not to do

Never pour paint down a drain or a gully; it goes to a watercourse and it is an offence in most places.
Never put liquid paint in a wheelie bin — it bursts under compaction and the crew is entitled to refuse the whole load.

Kerbside collection rules genuinely vary by council and county, and local rules always win over general guidance. The reasoning above is what transfers — if your service differs, it will usually be for a reason described here.

Other things that go to household waste recycling centre

Car batteries (lead-acid) Garage, scrap yard or household waste centre. Lead-acid is the most successfully recycled consumer product there is.
Used motor oil Household waste centre oil bank, or a garage that accepts it. One container of it contaminates an enormous volume of water.
Small electricals (kettles, toasters, hair dryers) Electrical waste. Household waste centre, a shop take-back point, or a kerbside small-electricals sack if your council runs one.
Pyrex and heat-resistant glassware Never the glass bin. Ovenware is formulated not to melt like bottle glass, and one fragment can ruin a whole batch.
Televisions and monitors WEEE recycling. Old CRT sets contain several kilograms of leaded glass.
CFL energy-saving bulbs Household waste centre or a shop take-back point. They contain mercury and must not be binned.
LED bulbs Small electricals recycling. No mercury, but they are electronics, not glass.
Drinking glasses and wine glasses Not the glass bin. Tableware glass has a different composition from bottle glass.
Smoke alarms Household waste centre or manufacturer return. Ionisation alarms contain a tiny sealed radioactive source.
Crockery, mugs and ceramics Not glass and not recyclable at the kerb. Donate what is whole; broken pieces go to the household waste centre or general waste.
Fluorescent tubes Household waste centre, intact. Mercury inside, and a tube that breaks in transit is a spill.
Camping gas canisters and butane cartridges Household waste centre, as gas cylinders — not the metal skip and never a bin, whether or not they feel empty.
Fire extinguishers Household waste centre or a fire equipment company. It is pressurised until a professional has discharged it.
Mirrors Household waste centre. The reflective backing means it is not recyclable glass.

Common questions

Where do Leftover wet paint go?: Household waste centre or a community paint reuse scheme. Liquid paint is not accepted in any household bin.
What happens if you put Leftover wet paint in the wrong bin?: Never pour paint down a drain or a gully; it goes to a watercourse and it is an offence in most places. Never put liquid paint in a wheelie bin — it bursts under compaction and the crew is entitled to refuse the whole load.

Where do Car batteries (lead-acid) go? Garage, scrap yard or household waste centre. Lead-acid is the most successfully recycled consumer product there is.
Where do Used motor oil go? Household waste centre oil bank, or a garage that accepts it. One container of it contaminates an enormous volume of water.
Where do Small electricals (kettles, toasters, hair dryers) go? Electrical waste. Household waste centre, a shop take-back point, or a kerbside small-electricals sack if your council runs one.
Where do Pyrex and heat-resistant glassware go? Never the glass bin. Ovenware is formulated not to melt like bottle glass, and one fragment can ruin a whole batch.
Where do Televisions and monitors go? WEEE recycling. Old CRT sets contain several kilograms of leaded glass.
Where do CFL energy-saving bulbs go? Household waste centre or a shop take-back point. They contain mercury and must not be binned.
Where do Household batteries (AA, AAA, C, D, 9V) go? Shop or manufacturer take-back
Where do Lithium-ion batteries go? Shop or manufacturer take-back
Where do Vapes and disposable e-cigarettes go? Shop or manufacturer take-back
Where do Medicines and tablets go? Pharmacy
Where do Pizza boxes go? Kerbside recycling bin
Where do Mobile phones go? Shop or manufacturer take-back

Sources

US Environmental Protection Agency — EPA (Public domain (US Government))

How these figures are compiled and checked