When should I buy a cot bed mattress?
Short answer: Buy in time for when you will first use it: from birth through the cot and toddler-bed years. For newborn essentials, many parents order in the second trimester to allow for delivery and assembly.
- Confirm the cot bed's mattress size before buying, as frames vary.
- Firm, flat, waterproof, with a snug fit.
- Choose foam, spring or fibre for your budget and how much you need to wipe or wash it.
What the guidance says
- 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.
- The Lullaby Trust says your baby's head should sink no more than a few millimetres into the mattress.
- The Lullaby Trust recommends a new mattress for each baby where possible. A second-hand one should have a 100% waterproof cover, no rips, tears or water damage, no sagging, a good fit and a fire-resistant label.
Related questions
What is a cot bed mattress?
A firm, flat mattress for a cot bed, usually 140 x 70cm, which carries on into the toddler-bed stage.
Shop at Baby Kingdom
- Ickle Bubba Premium Sprung Cot Mattress 140 x 70cm
- Kidsaw Freshtec Starter Foam Toddler Cot Bed Mattress
- Tutti Bambini Eco Fibre Deluxe Cot Bed Mattress (70 x 140 cm)
- Ickle Bubba All Seasons Premium Pocket Sprung Mattress 140 x 70cm
Check each product page for its exact dimensions, mattress size, age and weight limits and safety standards.
More advice
Can my baby sleep on a bean bag?Can I put a mattress in a travel cot?Is a cot mattress right for you? Quick quizIs a cot bed mattress right for you? Quick quizIs a cot 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)
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.