Cheapest place to buy a mattress in the UK

A category where the discount is permanent and the model numbers are designed not to match.

Updated 2 September 2026 · 3 min read

The permanent sale

Mattresses are the clearest example of a category where the advertised discount is close to meaningless. Reductions run more or less continuously, which means the crossed-out price is not a price anybody was recently paying — it is the reference point the offer is measured against.

Treat the discounted figure as the price and ignore the reduction entirely. Comparing "how much off" tells you nothing here; comparing what you actually pay tells you everything.

Why cross-shop comparison barely works

Bed retailers commonly sell exclusive models, or the same manufacturer's product under a retailer-specific name. Two mattresses can share construction, materials and firmness and carry entirely different names in two shops. There is frequently no identical product to compare against.

What actually determines value

• Construction type — pocket sprung, open coil, memory foam, latex, hybrid. This matters far more than brand.
• Spring count, which is widely advertised and less meaningful than it looks — count without gauge and layout tells you little.
• Foam density and depth for foam mattresses, which are the honest specification and rarely the headline.
• The trial period. A mattress cannot be judged in a showroom. A genuine home trial with free returns is worth more than a discount.
• Delivery, and removal of the old mattress, which carries a real cost and differs between retailers.

Boxed mattresses

Compressed, boxed mattresses removed a lot of cost from the traditional model and created a competitive online market. They are genuinely worth considering, and they come with their own things to check: how long it needs to expand, the trial length, and who collects it if you send it back.

UK sizes differ from European ones, and the names collide

A UK king and a European king are not the same dimensions, and a UK double is not a continental double. Mattresses sold by pan-European retailers are frequently listed in continental sizes using British names, which means the bed frame you own will not fit — or the fitted sheets will not. The dimensions in centimetres are the only reliable check, and the size name is not.

Trial periods are worth more than the discount

Several manufacturers offer a genuine sleep trial of a hundred nights or more with free collection, which solves the fundamental problem that you cannot tell whether a mattress suits you in a showroom. A mattress that costs more but can be returned after two months is a materially better purchase than a cheaper one you are stuck with. Read what the trial actually requires — many need a mattress protector used throughout.

What the specifications mean

• Spring count is nearly meaningless above a certain point and is heavily inflated by counting mini-springs in layers.
• Pocket springs move independently, which is what stops you rolling towards a partner; open coil does not.
• Firmness ratings are not standardised between manufacturers, so a firm from one is a medium from another.
• Your weight changes which firmness suits you, which is why a single recommendation for a shared bed is difficult.

Before you buy

1. Write down the specification, not the model name.
2. Compare what you pay, never the size of the discount.
3. Check the trial period and who pays return collection.
4. Add delivery and old-mattress removal to both sides of the comparison.