How to get urine out of a mattress
The stain is easy and the smell is the problem, because it comes from compounds that ordinary cleaners dilute rather than break down.
Why the smell comes back
Urine leaves uric acid crystals in the fillings. Water and detergent dilute them; they do not destroy them. So the mark disappears, the mattress dries, and weeks later humidity reactivates the crystals and the smell returns.
An enzyme cleaner breaks them down. That is the difference between cleaning and masking.
The rule that governs all of this
A mattress cannot be properly dried at home. Water goes in easily and comes out slowly, and once moisture reaches the foam or the spring unit it can sit there for days.
That is how mould grows inside a mattress, which is worse than the stain you were treating and cannot be reversed. Use the least liquid that works, and dry it completely.
The method, in order
Act fast. Almost everything is easier wet than dry, and most of the difficulty in stain removal is that the stain has set.
Blot, never rub. Press a dry towel down hard and lift. Rubbing pushes liquid deeper into the fillings and spreads the mark outward, turning a small problem into a large one.
Work from the outside inward, so you do not spread the edge.
Use a lightly damp cloth, never a soaked one, and never pour anything onto a mattress.
Test on a hidden area first, usually the underside near a corner.
A fresh accident
Strip the bed and blot immediately, pressing hard with towels and standing on them if necessary. Getting liquid out before it spreads is most of the job.
Apply an enzyme cleaner, following the product's dwell time, which is usually ten to fifteen minutes. Enzymes need time and moisture to work, so do not blot it off immediately.
Blot away the excess with a clean damp cloth.
Sprinkle bicarbonate of soda lightly over the area once it is no longer wet, leave an hour, and vacuum thoroughly. This takes residual odour and moisture.
Then dry it properly, which for urine matters more than for anything else on this site, because the liquid volume is larger and it has usually soaked deeper than you think.
An old or dried stain
The visible mark is usually yellow-brown and the smell is the real target.
Enzyme cleaner is still the answer, and it needs longer. Dampen the area lightly first so the enzymes can reach the crystals, apply, and cover with a damp cloth to stop it drying too fast.
Expect to repeat it. Two or three mild applications outperform one heavy soaking, which only pushes the problem deeper.
A white vinegar and water solution is the common home remedy. It helps with odour and it does not break down uric acid, so it is a partial fix that smells strongly itself for a day or two.
Drying, which is the step that actually matters
This is where mattresses are lost, and it is the step people skip because the stain has gone and the job feels finished.
Open a window and put a fan across the surface. Moving air does far more than heat.
Leave the mattress uncovered and unmade for as long as it takes, which can be a full day for anything more than a small mark.
Stand it on edge if you can, so both faces are exposed.
Do not put bedding back on a damp mattress. A made bed over damp fillings is the exact condition mould needs.
Avoid a hairdryer held close, because heat can damage foam. Ambient airflow is better and safer.
What never to use
A steam cleaner. It drives moisture deep into the fillings and the spring unit, causing mould and rust. Manufacturers frequently prohibit it, and using one can void your guarantee. This is the most common way people destroy a sound mattress while trying to help it.
A carpet washer or wet vacuum. Same problem, more water.
Bleach or strong solvents. They damage foam and fabric and can discolour permanently.
Large amounts of bicarbonate of soda left for hours. It absorbs moisture, and what stays in the fabric attracts more later. A light sprinkle, an hour, then thorough vacuuming.
If this is a recurring situation
For children, and for anyone dealing with incontinence, the practical setup matters more than any cleaning technique.
A waterproof protector, fitted before the first night, and a breathable membrane rather than a plastic-backed layer, which traps heat and moisture and makes the bed clammy.
Buy two protectors and two fitted sheets. Changing a bed at 3am is far easier when the spare is clean, and this is the single most useful thing on this page.
Layer them: protector, sheet, second protector, second sheet. At 3am you strip the top two layers and the bed is made.
Bedwetting in children is common and usually resolves with time. If it is persistent, starts again after a dry period, or comes with pain or increased thirst, that is worth raising with a GP or health visitor.
Before you treat anything under guarantee
A stain voids most mattress guarantees absolutely. If the mattress is under guarantee and visibly damaged, photograph it and speak to the retailer before cleaning, because cleaning alters the evidence.
Your statutory rights sit with whoever sold it to you rather than the manufacturer. Under the Consumer Rights Act 2015 you have up to six years to bring a claim in England, Wales and Northern Ireland, five in Scotland, so keep the proof of purchase.
This is general information rather than legal advice, and Citizens Advice is the right starting point for a specific situation.
Prevention is the only strategy that works
Since there is no home deep clean, the protector is the whole game, and at 20 to 40 pounds it is the highest ratio of value to cost anywhere in bedding.
Buy a breathable protector, not a cheap plastic-backed one. A breathable membrane passes water vapour while blocking liquid; a laminated layer blocks air too and makes the whole bed warmer and clammier.
Buy two, so one is always clean. A protector in the wash is a mattress unprotected.
Check the depth. Modern hybrids run 28 to 35 centimetres and most protectors are cut for around 25, and one that pings off a corner ends up in a drawer.
Related reading
Other stains
Protection
How this site works
Nothing here is paid for by a brand. No manufacturer has copy approval, a preview, or the ability to change a score, and where a link earns a commission that never changes a ranking.
Where a brand does not publish a specification, that is stated rather than estimated, because an absent number is itself information. The corrections log and the products I will not recommend page are both public.
Questions people ask
How do you get urine smell out of a mattress?
With an enzyme cleaner, which breaks down the uric acid crystals that cause the odour. Water and ordinary detergent only dilute them, which is why the smell returns weeks later when humidity reactivates them.
Does vinegar remove urine from a mattress?
It helps with odour and does not break down uric acid, so it is a partial fix. An enzyme cleaner is the only thing that destroys the compounds causing the smell rather than diluting them.
Why does the urine smell come back after cleaning?
Because uric acid crystals remain in the fillings. They are reactivated by humidity, which is why a mattress that smelled fine in summer can smell again in damp weather.
What is the best setup for a child who wets the bed?
Layer protector, sheet, protector, sheet, so at 3am you strip the top two layers and the bed is made. Use breathable waterproof protectors rather than plastic-backed ones, and own two of everything.