Can my baby sleep on a waterproof mat in the cot?
Short answer: Use a fitted waterproof mattress protector rather than loose mats. The surface must stay firm and flat, with nothing loose.
Here is the detail behind that answer, taken from current UK guidance from the NHS and the Lullaby Trust.
Things to check
- Measure the inside of the cot. The mattress should fit with no gaps.
- Choose firm, flat and waterproof. Your baby's head should sink no more than a few millimetres.
- Check for a fire-resistant label and the relevant British Standard.
What the guidance says
- The Lullaby Trust recommends a waterproof mattress protector, because it can be wiped clean.
- Keep the cot clear: no pillows, duvets, cot bumpers, loose blankets, soft toys, pods, nests, wedges or anything to keep your baby in place.
Related questions
What is a cot mattress?
A firm, flat mattress for a standard cot, usually 120 x 60cm.
Shop at Baby Kingdom
Browse cot mattresses 120 x 60
- Ickle Bubba Premium Sprung Cot Mattress
- Ickle Bubba All Seasons Premium Pocket Sprung Mattress
- Tutti Bambini Natural Coir Fibre Cot Mattress (60 x 120 cm)
- Obaby Eco Foam Cot Mattress 120 x 60 cm
Check each product page for its exact dimensions, mattress size, age and weight limits and safety standards.
More advice
Travel cot mattress vs cot mattress: which is better?Do I need a waterproof mattress protector for a cot?Which baby mattress size do you need?Can I buy a second-hand travel cot mattress?Is a Moses basket mattress right for you? Quick quizCrib and Moses basket mattresses buying guide for UK parentsAll cot and baby mattresses advice →
Sources
- The Lullaby Trust: Baby mattresses and bedding (accessed 2026-10-21)
- NHS: Sudden infant death syndrome (SIDS) (accessed 2026-10-21)
General information only, not medical advice. Always follow your product's instructions. If you are worried about your baby, contact your GP, health visitor or 111. In an emergency, call 999.