Cot bed mattresses buying guide for UK parents
Short answer: A cot bed mattress is a firm, flat mattress for a cot bed, usually 140 x 70cm, which carries on into the toddler-bed stage. Choose one that fits your space and your baby's stage, and use it as the instructions say.
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. It is used from birth through the cot and toddler-bed years.
How to choose
- 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.
Safety standards
- Mattresses: look for BS 7177:2008+A1:2011, and BS EN 16890:2017+A1:2021 for cot, travel cot and crib mattresses.
Common questions
- Do I need a new mattress for my second baby?
- What size is a cot bed mattress?
- How do I choose a cot bed mattress?
- How long can you use a cot bed mattress?
- When should I buy a cot bed mattress?
- Can I buy a second-hand cot bed mattress?
- Cot bed mattress buying checklist
- What safety standard should a cot bed mattress have?
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.
- Mattresses: look for BS 7177:2008+A1:2011, and BS EN 16890:2017+A1:2021 for cot, travel cot and crib mattresses.
Shop at Baby Kingdom
- Tutti Bambini Pocket Sprung Cot Bed Mattress (70 x 140 cm)
- Tutti Bambini Natural Coir Fibre Cot Bed Mattress (70 x 140 cm)
- Obaby Eco Foam Mattress - 140 x 70cm
- Tutti Bambini Eco Fibre Deluxe Cot Bed Mattress (70 x 140 cm)
Check each product page for its exact dimensions, mattress size, age and weight limits and safety standards.
More advice
What mattress protectors does Baby Kingdom sell?How long can you use a Moses basket mattress?Moses basket mattress vs cot mattress: which is better?How do I clean a cot mattress?Can I buy a second-hand travel cot mattress?Is a travel cot mattress right for you? Quick quizAll 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.