Do I need a waterproof mattress protector for a cot?
Short answer: The Lullaby Trust recommends a waterproof mattress protector, because it can be wiped clean. It should keep the surface firm and flat.
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.
- Use a firm, flat, waterproof mattress in good condition, with no raised or cushioned edges, that fits the cot or Moses basket with no gaps.
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
- Obaby Eco Foam Cot Mattress 120 x 60 cm
- Tutti Bambini Natural Coir Fibre Cot Mattress (60 x 120 cm)
- Obaby Foam Cot Mattress 120 x 60 cm
- Obaby Fibre Mattress - 120 x 60cm
Check each product page for its exact dimensions, mattress size, age and weight limits and safety standards.
More advice
Can a 2 week old sleep on a raised or tilted mattress for reflux?What size is a cot mattress?Is a cot mattress right for you? Quick quizCot mattress buying checklistGuide to cot mattresses: what to look forCot bed mattresses buying guide for UK parentsAll cot and baby mattresses advice →
Sources
- The Lullaby Trust: Baby mattresses and bedding (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.