Why are mattresses always on sale?

Continuous discounting makes the higher reference price the number the offer is judged against. Because it runs more or less permanently, the "was" price is not one many people were paying — so compare what you actually pay instead.

How do I compare mattresses between shops?

Usually you cannot compare by name, because retailers sell exclusive models. Compare specification instead: construction, spring gauge and layout, foam density and depth, cover and firmness.

Is a boxed mattress as good as a traditional one?

They can be, and the format removed real cost from the supply chain. Check the expansion time, the length of the home trial, and who pays for collection if you return it.

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 · 2 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.

Before you buy

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