Bed-in-a-box mattresses: unboxing, expansion time, smells and trials

A bed-in-a-box mattress — also called rolled, roll-packed or vacuum-packed — is compressed, rolled up and boxed at the factory, which makes it much easier to get up the stairs. The National Bed Federation (NBF) notes that "many foam mattresses are available to buy rolled-up", and some sprung mattresses are sold this way too: IKEA's VADSÖ open coil mattress, for example, is roll-packed.

How long before you can sleep on it?

Follow the maker's instructions, because it varies:

IKEA says its mattresses "can be used immediately", but a packaged mattress "only regains its full shape and comfort after approximately 72 hours".
Silentnight says you should wait "4 to 24 hours for a rolled memory foam mattress to properly expand".

Your body also needs time to adjust to any new mattress — a couple of weeks, according to IKEA; "a few weeks", says the NBF.

That new-mattress smell

Rolled foam mattresses can smell when first unpacked. The NBF says the smell comes from chemicals in the foam reacting with air once the packaging is opened, that it "is harmless to health and will disappear", and that it can take up to a week to go completely. Air the room as much as you can.

Don't roll it up again

The NBF warns against bending or rolling a mattress, because it can damage the spring unit and invalidate warranties. If you send a rolled mattress back under a trial, use the retailer's collection arrangements rather than trying to re-roll it.

Home trials

Because you can't try a boxed mattress in a shop, many sellers offer a home trial. These are the seller's own offers and the terms differ. On the makers' own websites on 3 October 2026, for example:

Emma listed a 200-night trial on its Original mattress;
Dormeo offered a 200-night comfort guarantee on its mattresses (not on clearance items or non-mattress products such as pillows);
Silentnight listed a 60-night sleep trial.

Check who collects the mattress, whether there's a charge, and whether you must keep it for a minimum time before returning it.

Your legal cooling-off period

Separately from any trial, Citizens Advice explains that you automatically get a 14-day cooling-off period when you buy something you haven't seen in person, unless it's bespoke or made to measure. There are exceptions — including an item with a broken hygiene seal — and a business must tell you before you buy if an item doesn't have a cooling-off period.

Spotting a too-good-to-be-true offer

The NBF advises being "wary of discounts claiming to be up to 70 or 80 percent off RRPs and time limited offers that pressure you into ordering now", and reminds buyers that "a really cheap offer is cheap for a reason". It also suggests checking the seller has full contact details and clear returns terms.