What Safety Standards Does a UK Cot Mattress Need to Meet?
A UK cot mattress should meet BS EN 16890:2017, the British and European safety standard for children's cot and crib mattresses. It tests for hazards such as entrapment, suffocation and choking, and checks that the sleep surface holds its shape. All Boori cot mattresses comply with it. UK cot mattresses must also meet the fire safety rules in the Furniture and Furnishings (Fire) (Safety) Regulations 1988.
Your little one's safety is the most important consideration when choosing a cot or cot bed mattress, that's why all our British-made mattresses meet BS EN 16890:2017. They've been tested with specialist machines designed to ensure they offer maximum support and comfort for your baby.
Families often choose a baby cot mattress that has a firm feel and stays supportive underweight. A stable surface helps your baby rest safely, especially in the early months when posture and breathing need gentle protection. Many parents use a breathable protector from the mattress protectors collection to keep the sleep area clean between washes.
Choose from a range of features including mattresses treated with a unique Purotex technology which is an hypo-allergenic treatment that uses probiotics to reduce moisture build up and create a barrier against dust and allergens, stopping them from penetrating the mattress.
In addition to the core design, some families prefer treatments that maintain freshness. Hypoallergenic technology helps reduce unwanted allergens and moisture, especially in homes with varying temperatures. These small differences make daily care lighter and give peace of mind through long nights and busy mornings.
What Size Cot Mattress Do I Need for a UK Cot or Cot Bed?
The cot mattress you need is the one sized for your exact cot. These are the main UK sizes:
- Standard cot bed: 140x70cm, the most common UK size. Boori cot beds take a 132x70cm mattress.
- Compact cot: 119x65cm, used across Boori's space-saving cots.
- Oval cot (Boori Oasis): about 119x64cm, oval shaped and made for Boori oval cots only.
- Bassinet: much smaller, at around 80x40cm. Check the bassinet product page for the exact size.
UK cot mattress sizes differ from European and Australian sizes. A mattress sold as "cot bed size" by an EU or AU retailer may not fit a UK cot. An oval mattress never fits a rectangular cot, and a rectangular mattress never fits an oval one.
Always order the mattress specified for your Boori cot model. The size is listed on the cot product page, in the assembly instructions and on the packaging.
How Do I Check a Mattress Fits My Cot Properly?
A mattress fits properly when it sits flat inside the cot with no large gaps at the sides or ends. Push the mattress into one corner, then check the gap on the opposite side and end.
A cot bed mattress should match the internal length and width of your cot so there are minimal gaps at the sides. The fit of a baby cot mattress within the cot frame is very important, as it ensures that the cot and mattress combination is safe to use together. When shopping for a cot, the product information will generally specify the correct mattress dimensions you require. Additionally, the packaging and the assembly instructions that the cot comes with will also state the recommended mattress size.
A cot bed mattress that fits neatly keeps movement stable and prevents rolling gaps. Before choosing a mattress, measure the internal space of your cot and confirm the size notes listed on the product page. If you are using bed cots with mattress already included, the sizing is usually matched for you, making setup faster.
For families who travel between homes or spend nights away, a travel cot mattress sized correctly for your portable cot helps your baby sleep more naturally in different environments. It can be stored easily and brought out whenever needed.
What Is the 25mm Gap Rule for Cot Mattresses?
The 25mm gap rule means the mattress should fit the cot with no gap larger than 25mm on any side. A bigger gap can trap a baby's head, arm or leg between the mattress and the cot frame.
BS EN 716 sets the safety requirements for UK cots, and The Lullaby Trust advises a mattress that fits the cot with no gaps. Keeping every side under 25mm is a simple way to meet both.
- Measure the inside of the cot, not the outside of the frame.
- Never swap in a different size, even if it looks close.
- Never put a standard mattress in a compact or oval cot.
- Recheck the fit after moving the base to a lower height.
How Firm Should a Cot Mattress Be?
A cot mattress should be firm, not soft and not memory foam. Press the centre of the mattress with your hand. It should spring back straight away and leave no lasting dent.
A soft mattress can sink under a baby's weight and form a hollow around the face. The Lullaby Trust advises a firm, flat surface for every sleep in the first 12 months, and BS EN 16890:2017 includes checks that the surface keeps its shape.
A firm sleep surface is important for providing the baby with a safe sleep environment that minimises the risk of SIDS and suffocation. The cot mattress should support the baby's shoulders, hips and legs without dipping. Make sure the sleep area is kept clear, with only the essential bedding items. Adding unnecessary items such as toys or pillows to the cot increases the risk of suffocation and should be avoided.
A stable cot mattress supports growing joints and helps babies shift into different sleeping positions without sinking. For bedding, many families choose breathable cotton sets from the quilt cover set collection. These keep the sleep area light while staying easy to wash.
Some parents use a travel cot with mattress option for naps in different rooms of the home. This keeps routines consistent whether the sleep happens upstairs, in the living area, or during a visit to family.
What Does The Lullaby Trust Recommend for a Baby's Cot?
The Lullaby Trust (lullabytrust.org.uk), the UK's safer sleep charity, recommends a firm, flat mattress that fits the cot with no gaps. Its core advice for babies under 12 months is:
- Place your baby on their back for every sleep.
- Use a firm, flat, waterproof mattress in good condition.
- Keep the cot clear: no pillows, bumpers, duvets or soft toys.
- Keep the room at 16 to 20°C.
- Place your baby with their feet at the foot of the cot.
A fitted baby sleeping bag in the right TOG keeps your baby warm without loose covers. You can find these in our muslins, blankets and sleeping bags range.
The Lullaby Trust also suggests a new mattress for each new baby where possible. If you reuse one, make sure it is firm, flat, clean and not damaged.
What Size Mattress Does a Travel Cot Need?
A travel cot needs a mattress made for its own internal size, which is different from a home cot. Common UK travel cot mattress sizes are 95x65cm and 120x60cm.
A standard Boori cot mattress (132x70cm, 140x70cm or 119x65cm) will not fit a travel cot correctly. Always measure your travel cot inside the frame before buying a mattress for it.
The thin mattress that comes with most travel cots is fine for the odd night away. For regular use, choose a firm travel cot mattress in the exact size. Never add a second mattress or padding on top of the one supplied. Boori does not currently sell a dedicated travel cot range.
How Do I Set Up a Cot Mattress Safely?
Set up a cot mattress by following the cot manual for base height and fitting the mattress flat with the right bedding. Lower the base as soon as your baby can sit or pull up.
Infant sleep surfaces used with a cot mattress are designed to comply with BS EN 16890:2017, and clear product notes help you set up with confidence. Always follow the mattress height and cot setting in your manual so the sleep space feels safe for every nap and night.
Stable settings and firm sides help the mattress remain level. Keep the frame at the correct height for your baby's stage so they can sleep safely and comfortably. If you rotate between rooms or layouts, a mattress for travel cot helps maintain the same firmness and feel wherever sleep happens.
Which Bedding Goes on a Cot Mattress?
A cot mattress needs a waterproof protector and a fitted sheet in the same size, and nothing else under 12 months. Keep two protectors and three sheets so you always have a clean set ready.
Sheets that fit well save time at night, and you can match sizes easily in Cot & Cot Bed Fitted Sheets. Keep spare sets close by in simple baskets, and a small unit from Nursery Storage helps you reach what you need in the Baby Changing area without turning on bright lights.
Soft fitted sheets from the cot bed fitted sheets range stay secure during movement and make quick changes easier. Families often keep a second set folded inside the cot drawer or changing area so everything is within reach.
Clear pathways, calm lighting, and small storage baskets help you manage night time needs without waking your baby fully.
Which Type of Cot Mattress Should I Choose?
Choose a fibre-filled mattress for a firm, lighter option, or a pocket spring hybrid for extra support and airflow. Both types are firm enough for newborns when made to BS EN 16890:2017.
- Fibre-filled cot mattresses: we have a range of fibre-filled cot mattresses, handmade with different fibre-fill options that create a firm and supportive sleep surface that also features hypo-allergenic properties. The material allows for good airflow in bed cots with a mattress, while the internal waterproof membrane protects the core.
- Pocket Spring and Fibre Hybrid mattresses: this cot mattress combines the support of a pocket spring mattress with the added support of an extra fibre-filled layer, allowing for improved airflow and comfort.
Different materials suit different family routines. A firmer cot mattress may benefit newborns, while a hybrid option can offer extra comfort for older babies. Families who travel often appreciate how a travel cot mattress offers consistency when sleeping away from home.
How Do I Care for a Cot Mattress?
Care for a cot mattress by keeping it covered with a waterproof protector, airing it often and turning it every few weeks. Replace it if it sags, stays damp or no longer springs back.
The cot mattress options we range use materials that promote breathability and airflow, but they can still be affected by overly moist conditions. To better protect your cot mattress from mould growth, make sure to keep the nursery well ventilated and occasionally air out the mattress. Also consider using a mattress protector to protect the mattress from any spills or leaks. To promote even wear across the surface, it is also best to occasionally rotate the mattress.
Families often rotate mattresses every few weeks to keep the core even. Ventilation helps the structure remain fresh, and breathable protectors reduce dampness after night time spills.
Where Should the Cot Go in a UK Nursery?
Place the cot away from radiators, heaters, windows and blind cords, with good airflow around it. A room thermometer helps you keep the nursery at 16 to 20°C.
Place the cot where the air feels fresh and the light is soft so the cot mattress feels welcoming at bedtime. Keep a chair nearby for soothing, and keep night items in one place so your hands can reach them while your baby stays settled.
Calm surroundings help bedtime run smoothly. Keep unnecessary items out of the cot, use soft light, and keep pathways clear so everything feels safe and predictable.
How Does Boori Deliver Cot Mattresses in the UK?
Boori delivers cot mattresses free to mainland UK, with no minimum spend. Large items usually arrive in 7 to 10 business days by our furniture courier. A surcharge applies to some Scottish Highlands and islands postcodes.
Delivery is made to your front door, with typical processing taking 1-3 business days before dispatch. Delivery typically occurs 7 to 10 business days after the item ships from the warehouse. It is best to check delivery timeframes and expectations for your address.
Boori does not offer in-house assembly, and the team can recommend experienced third-party assemblers for furniture if you want help. Weekday support can assist with parts or delivery questions for items that sit near your cot mattress.
What Warranty Comes with a Boori Cot Mattress?
The warranty for your cot mattress is shown on its product page. Most Boori furniture comes with 3 years of cover, which you can extend to 5 years by registering your product.
Warranty time frames vary by category, ranging from 1 to 5 years, as listed on product pages. Registering eligible items can extend coverage for many timber pieces in your nursery plan. For any setup questions, you can contact the team on weekdays, so your cot mattress is set up in a clear, simple plan.
What Should I Check Before Buying a Cot Mattress?
Small, clear checks make choosing easy and help the first night run smoothly.
- Correct Size: Measure the internal length and width of your cot, then match them to the listing so the cot mattress fits the frame without gaps.
- Right Depth: Check the depth in the product notes so the top sits at the safe level for your cot setting and your reach.
- Sheet Fit: Select fitted sheets in the same size range to ensure the corners stay secure after washing and drying.
- Easy Clean: Add a breathable protector and keep one spare ready so night swaps are fast and quiet.
- Storage Plan: Place spare bedding in one basket and nappies in another, so you can easily find what you need in low light.
- Standard Met: Check the product page confirms BS EN 16890:2017.
- Press Test: The surface should spring straight back with no dent.
Can I Buy a Boori Cot Mattress Near Me?
Boori UK is an online-only store, so there is no UK showroom. Every cot and cot bed mattress is available on this page with free delivery to mainland UK.
If you're looking to buy a cot mattress, check out the website for a range of supportive and hypo-allergenic options. We unfortunately do not have a showroom or store where the mattresses can be seen and touched, but they all feature a firm sleep surface, in line with recommendations.