The Most Common Mattress Buying Mistakes — And How to Avoid Them

The Most Common Mattress Buying Mistakes — And How to Avoid Them

Buying a mattress should, in theory, be one of the easier purchases you make for your home. You know the size of your bed, you have a rough idea of what you want to spend and, somewhere between “soft” and “sleeping on a wooden floor”, you probably know what feels comfortable.

Then you actually start shopping.

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Suddenly there are pocket spring counts to compare, memory foam layers to investigate, medium-firm mattresses sitting alongside firm and extra-firm versions, pillowtops, natural fillings, orthopaedic models and enough technical terminology to make choosing somewhere to sleep feel rather more complicated than it ought to be.

The temptation is to find one simple measure of quality and cling to it. Perhaps the mattress with the most springs must be best. Perhaps firm is better for your back. Perhaps the most expensive one will inevitably be the most comfortable, or the thickest mattress will feel the most luxurious.

Unfortunately, mattresses don't work quite like that.

A very good mattress can still be completely wrong for the person sleeping on it, which is why many of the most common mattress buying mistakes have surprisingly little to do with buying a poor-quality product. More often, they come from choosing the wrong firmness, misunderstanding what the specifications mean, failing to consider how you actually sleep or overlooking practical details until the mattress is already on its way upstairs.

So, before you buy your next mattress, here are the mistakes worth avoiding — including a few that are remarkably easy to make.

Quick Answer: What Are the Biggest Mistakes People Make When Buying a Mattress?

The most common mattress buying mistakes include choosing firmness without considering your sleeping position and body weight, assuming firmer always means more supportive, buying according to spring count alone, ignoring mattress materials, choosing a mattress that is too small, forgetting your partner's preferences, failing to check the bed base and focusing too heavily on price or specifications rather than comfort.

It is also important to check measurements, mattress depth, delivery access and the retailer's returns policy before ordering.

In other words, don't begin with “Which mattress has the biggest number?”

Begin with “How do I actually sleep?”

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Mistake #1: Assuming a Firm Mattress Is Automatically Better

This is probably the most persistent mattress myth of all.

Somewhere along the way, firmness became confused with quality and support, which means shoppers sometimes approach mattress buying as though the objective is to find the hardest surface they can reasonably tolerate.

In reality, firmness describes how resistant a mattress feels, while support describes how effectively its construction responds to your body. They are related, but they aren't interchangeable.

A well-constructed medium mattress can be extremely supportive. A mattress that feels much too hard for your body can still be uncomfortable, however impressive its specifications might be.

Your sleeping position provides a much better starting point. Side sleepers often appreciate more cushioning around the shoulders and hips, whereas back and front sleepers may prefer greater resistance through the centre of the body. Body weight changes the experience again, since a lighter sleeper will generally compress a mattress less deeply than somebody heavier.

Online Bed Store's mattress collection reflects that variation, ranging from medium-soft options through medium and medium-firm to firm, extra-firm and ultra-firm mattresses.

At one end, the Heritage Natural 5000 Pocket Sprung Mattress provides a medium-soft feel for sleepers who prefer more cushioning. At the firmer end, the Hampton Orthopaedic Extra Firm Sprung Mattress is intended for people who deliberately want considerably more resistance.

And there really are people who do.

At the very firmest end of the scale, an ultra-firm mattress can offer something approaching that solid, almost floor-like sleeping sensation, with very little sink beneath the body. That sounds deeply unappealing to some sleepers and absolutely perfect to others, which rather proves the point: firmness isn't a hierarchy where harder equals better.

It is a preference.

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Mistake #2: Choosing Firmness Without Thinking About Your Sleeping Position

You may fall asleep neatly on your back every evening, but where are you when you wake up?

That is often the more useful question.

People tend to describe themselves as side, back or stomach sleepers as though they adopt one position at bedtime and remain perfectly still until morning. Many of us are combination sleepers who move repeatedly, although there is usually one position in which we spend more time.

That matters because different positions place pressure on different parts of the body.

When you sleep on your side, the shoulder and hip press further into the mattress, so a surface with some cushioning can accommodate those areas more comfortably. Back sleepers usually need a balance between contouring and resistance, while front sleepers often prefer enough firmness to prevent the central part of the body settling too deeply.

A medium mattress such as the Essentials Cool Touch 1000 Pocket Sprung Mattress could therefore be a sensible place to begin for somebody who moves between positions and wants a balanced feel, while a medium-firm model such as the Vitality Sensation 2000 Pocket Sprung Mattress provides more resistance without moving fully into firm territory.

Don't buy according to the position in which you think you ought to sleep. Buy for the way you actually spend the night.

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Mistake #3: Buying the Mattress With the Highest Spring Count

Mattress shopping loves a large number.

One thousand springs sounds impressive until you see 2,000. Then along comes 3,000, followed by 5,000, and before long it is easy to assume that mattress quality can be assessed rather like broadband speed: simply choose the largest number you can afford.

Spring count does matter, particularly when comparing the construction of pocket sprung mattresses, but it doesn't tell you everything about comfort, firmness or suitability.

OBS's own Heritage Natural range demonstrates this rather neatly. The Heritage Natural 2000 Pocket Sprung Mattress has a firm comfort level, while the Heritage Natural 3000 Pocket Sprung Pillowtop Mattress sits in the medium category and the Heritage Natural 5000 Pocket Sprung Mattress is medium-soft.

If spring count dictated firmness or automatically told you which mattress was “best”, that progression would make very little sense.

The finished feel is influenced by the springs themselves, their tension, the materials surrounding them, the comfort layers above them and the overall mattress construction. A pillowtop can create a different surface sensation from a flatter mattress, while natural fillings and foam each respond differently beneath the body.

Spring count is useful information.

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Mistake #4: Ignoring What Is Above the Springs

Two mattresses can contain pocket springs, carry the same broad firmness rating and still feel completely different when you climb into bed.

This is where the comfort layers become important.

Memory foam has a more contouring quality and responds closely to the body, while natural fillings can produce a more traditional, breathable mattress feel. Pillowtops introduce an additional cushioned surface layer, and cooling materials may appeal to sleepers who frequently feel warm at night.

Take the Stafford 1000 Pocket Memory Sprung Mattress as an example. It combines a pocket spring system with memory foam and sits within the medium-firm category. Someone who enjoys the closer, more enveloping sensation of foam may prefer that construction to another medium-firm mattress with a more traditionally sprung surface.

Meanwhile, a mattress such as the Heritage Natural 3000 Pocket Sprung Pillowtop Mattress uses a different approach, combining its pocket spring system with natural fillings and a pillowtop finish.

Neither specification is universally better.

The question is whether you enjoy lying on it.

This is one of the reasons buying a mattress purely by comparing technical specifications can lead you astray. Specifications tell you how the mattress has been built. They don't tell you whether you personally enjoy the resulting sensation.

Mistake #5: Choosing the Mattress Before Thinking About Your Partner

There are few purchases where two people's preferences are so casually expected to become one.

One partner sleeps on their side and wants cushioning around the shoulder. The other sleeps on their back and would happily choose something approaching concrete. One is always cold, the other spends half the night kicking the duvet away, and somehow both are expected to agree that “medium-firm” sounds about right.

If you share a mattress, both people need to be part of the decision.

Where your preferences are relatively close, medium or medium-firm can provide a useful compromise. Pocket sprung mattresses are also worth considering because the individual springs respond independently, which can reduce the amount of movement travelling across the mattress when one person turns over.

If your preferences are dramatically different, however, compromising may leave neither of you particularly happy.

This is where a zip and link mattress can be useful. Two separate mattress sections are connected to create one larger sleeping surface, potentially giving couples greater flexibility than a conventional one-piece mattress.

The person who wants more cushioning doesn't necessarily have to win.

Neither does the person campaigning for the hardest mattress in Yorkshire.

Mistake #6: Buying a Mattress That Is Too Small

People often choose mattress size according to what will physically fit into the room.

That is obviously important, but it is only half the calculation.

A double mattress may fit perfectly well between two bedside tables, but if two adults regularly wake one another because there isn't enough personal sleeping space, technically fitting the room isn't much consolation.

Standard UK mattress sizes increase substantially as you move upwards. A double measures approximately 135 x 190cm, while a king gives you around 150 x 200cm and a super king around 180 x 200cm.

That extra width can make a noticeable difference for couples, particularly if one or both sleepers move frequently. Moving from double to king also gives you extra length, which taller sleepers may appreciate.

Of course, bigger isn't automatically better either. A super king squeezed into a modest bedroom can leave so little space around it that the room becomes awkward to use.

Measure the bedroom, but think about the humans as well.

Mistake #7: Measuring the Old Mattress and Assuming That's Enough

You already have a double bed, so you order another double mattress.

Simple.

Usually.

The problem is that people occasionally discover that what they have been calling a double isn't quite what they thought it was, particularly with older frames, imported furniture, non-standard beds or mattresses that have been in the house so long nobody remembers where they came from.

Before ordering, check the internal dimensions of the bed frame or the specification of the base rather than relying solely on the label attached to the existing mattress.

Also check the mattress depth.

A substantially deeper mattress can change the finished height of the bed, cover more of an upholstered headboard than expected or make fitted sheets you already own frustratingly shallow. If the bed itself is already relatively high, adding a particularly deep mattress can produce a sleeping surface that feels very different to climb into.

A tape measure used before checkout can prevent a surprisingly expensive amount of annoyance afterwards.

Mistake #8: Forgetting About the Bed Base

The mattress gets all the attention because it is the part you sleep directly on, but it doesn't operate in isolation.

The base underneath provides the foundation.

Most OBS mattresses can be paired with common bed types including ottoman beds, divan beds, upholstered frames, wooden frames and metal frames, provided the size and support are appropriate. If you are placing a new mattress on an existing bed, however, inspect the base before assuming the mattress is responsible for every comfort problem.

Are the slats intact and correctly spaced?

Has the divan base developed damage or sagging?

Is the centre support doing its job?

Does the manufacturer specify particular base requirements?

Putting an expensive new mattress onto a tired or unsuitable foundation is rather like buying new carpet while ignoring the broken floorboards underneath.

If both mattress and base are approaching the end of their useful life, replacing them together may make more sense.

Mistake #9: Assuming Memory Foam Means Soft

Memory foam has become so closely associated with sinking and contouring that people sometimes treat “memory foam” as though it were itself a firmness rating.

It isn't.

Memory foam describes the material and the way it responds to pressure and heat. It can be incorporated into mattresses with different overall comfort levels, including medium-firm designs.

The Stafford 1000 Pocket Memory Sprung Mattress, for example, combines memory foam with a pocket sprung support system while retaining a medium-firm overall feel.

This distinction matters if you like the pressure-relieving, body-contouring character of foam but don't want an especially soft bed. You don't necessarily have to choose between foam and firmness.

Similarly, a pocket sprung mattress isn't automatically firm simply because it contains springs.

Always read the comfort rating separately from the material description.

Mistake #10: Assuming an Orthopaedic Mattress Is Right for Everyone

“Orthopaedic” sounds reassuringly medical.

It can therefore be tempting to assume that an orthopaedic mattress is automatically the sensible choice for anybody concerned about their back, posture or general support.

In practice, comfort is far more individual.

OBS offers both the Hampton Orthopaedic Firm Sprung Mattress and Hampton Orthopaedic Extra Firm Sprung Mattress, which are useful choices for sleepers actively looking for that firmer, more resistant style of bed. That does not mean every person who experiences back discomfort should immediately choose extra firm.

A mattress that is too firm for your body can create uncomfortable pressure, just as one that is too soft may allow more sink than you prefer.

Persistent back or joint pain is also a medical issue rather than something a mattress label can diagnose, so seek appropriate professional advice where necessary rather than treating the word “orthopaedic” as a prescription.

Mistake #11: Shopping by Price Alone

There are two versions of this mistake.

The first is buying the cheapest mattress available and assuming all mattresses are broadly the same underneath the cover.

The second is assuming the most expensive mattress must automatically provide the best night's sleep.

Neither approach tells you very much about suitability.

Price can reflect materials, construction, spring systems, natural fillings, finishing and manufacturing complexity, but spending more doesn't magically override your own comfort preference. Someone who genuinely loves a straightforward medium pocket sprung mattress isn't obliged to enjoy a more elaborate model simply because it costs more.

Set a realistic budget, certainly, but compare what you are getting within it.

OBS's range includes traditional sprung, pocket sprung, memory foam, hybrid, orthopaedic, natural filling and pillowtop mattresses at different price points, which means you can compare construction as well as cost.

The objective isn't to buy the cheapest mattress.

Nor is it to buy the most expensive.

It is to spend your budget on the features that matter to you.

Mistake #12: Buying for How the Mattress Feels for 30 Seconds

There is a familiar ritual in bed shops where you sit on the edge of a mattress, bounce slightly, lie on your back for approximately half a minute and then announce that it seems comfortable.

Unfortunately, this bears relatively little resemblance to sleeping on it for eight hours.

If you are testing a mattress in person, lie in your normal sleeping position, not merely flat on your back because that feels like the proper way to conduct a mattress test. Give your body time to settle and pay attention to areas where you usually experience pressure.

If you are shopping online, the product description becomes more important. Look at the stated firmness, construction, materials and suitability rather than relying on words such as “luxury” or “premium”, which tell you rather less about how the mattress will actually feel.

Your midnight sleeping position matters more than your showroom posture.

Mistake #13: Not Checking the Returns Policy Before Ordering

This is not the most exciting part of mattress shopping, which is precisely why people skip it.

They shouldn't.

Mattresses are hygiene-sensitive products and return conditions can be different from those for ordinary furniture. Online Bed Store's current returns policy states that mattresses cannot be returned once opened, used or slept on unless they are faulty, so customers should understand the policy before removing packaging.

That makes doing your homework before ordering particularly important.

Check the size carefully. Read the firmness description. Compare the construction. Ask questions if you're uncertain.

OBS also advises customers to check product specifications before placing an order, and its customer service team can provide guidance if you need help choosing.

Five minutes spent reading the returns information is considerably preferable to discovering it when a super king mattress is already occupying most of your bedroom.

Mistake #14: Panicking When a New Mattress Doesn't Feel Exactly as Expected on Night One

A new mattress can feel different from the one you have just spent several years sleeping on, even if the old one was no longer particularly comfortable.

Your previous mattress may have softened, settled or developed dips gradually enough that your body became accustomed to them. Moving onto a fresh sleeping surface can therefore feel surprisingly unfamiliar.

OBS advises that new mattresses may go through a settlement period during the first four to six weeks, as fillings compress and soften slightly with normal use. Some compressed mattresses may also require 24 to 72 hours to expand fully after unpacking.

So don't assume that a mattress is defective simply because it feels a little different on its first evening.

Equally, genuine damage or faults should be reported promptly. OBS asks customers to inspect products on delivery and report delivery-related damage or missing parts within 48 hours.

Knowing the difference between normal settling and an actual problem saves a lot of unnecessary worry.

Mistake #15: Forgetting That Mattresses Don't Last Forever

A mattress rarely wakes up one morning and announces that it has retired.

The change is usually gradual.

The surface develops a dip. You begin rolling towards the same area. The support doesn't feel quite as consistent as it once did, or you wake up less comfortable than you remember. Since the deterioration happens slowly, it is remarkably easy to adapt to it.

OBS suggests that many mattresses may need replacing somewhere around seven to ten years, depending on their quality, usage, condition and changes in comfort.

Age alone isn't a reason to throw away a perfectly comfortable mattress, but it is worth paying attention to physical signs such as sagging, unevenness and a noticeable loss of support.

There is also a useful test that requires no measuring equipment whatsoever: notice how you sleep elsewhere.

If you repeatedly wake up feeling better after a night in a hotel or guest room than you do in your own bed, your mattress may deserve a closer look.

Mistake #16: Forgetting About Temperature

Some of us could sleep beneath three duvets in July.

Others appear to generate their own central heating.

If you regularly wake feeling too warm, mattress construction is worth considering alongside firmness.

Pocket sprung designs naturally contain spaces between the individual springs, while different comfort layers can influence how the sleeping surface feels. OBS also offers mattresses specifically designed around cooling, including the Essentials Cool Touch 1000 Pocket Sprung Mattress and models in the Cocoon cooling range.

This is another reason not to shop by firmness alone.

You might have correctly established that medium is your ideal comfort level, but there can still be several medium mattresses with very different constructions and characteristics.

Firmness narrows the search.

Materials help finish it.

Mistake #17: Forgetting to Think About Movement

If you sleep alone, this section may be of limited interest unless you have a particularly energetic dog.

For couples, it matters.

Movement from one side of a shared mattress can travel across the sleeping surface, which becomes particularly noticeable when one partner is restless, gets up earlier or changes position frequently.

Pocket sprung mattresses can help because each spring sits within its own fabric pocket and responds independently, rather than the entire spring unit moving together.

That doesn't mean every couple must buy the mattress with the largest possible spring count. It simply means the type of spring system is worth considering if partner disturbance is something you already notice.

Sometimes the most important mattress feature isn't what happens when you're sleeping.

It's what happens when the person next to you isn't.

Mistake #18: Forgetting About Delivery Day

You have measured the bed.

Excellent.

Now measure the route to it.

Mattresses are large, and premium mattresses with substantial spring systems, pillowtops and deeper constructions can also be heavy. The fact that a king mattress fits beautifully into the bedroom doesn't automatically mean it will sail gracefully around the bend in the staircase.

Think about doorways, hallways, stairs, bannisters, low ceilings and awkward turns before ordering, particularly with larger sizes.

This is also worth considering if you are choosing between a conventional large mattress and a zip and link mattress, since split mattress sections can be significantly easier to manoeuvre through difficult properties.

OBS's current returns policy places responsibility on customers for ensuring ordered furniture can pass through doorways, staircases and hallways, making access something to check before delivery rather than while two delivery drivers are standing at the bottom of the stairs.

Mistake #19: Keeping the New Mattress but Forgetting the Old One

The new mattress has arrived.

Everyone is delighted.

There is just one minor issue: the old mattress is now leaning against the landing wall like an enormous unwanted houseguest.

Think about disposal before delivery day.

Mattresses are bulky and can't simply disappear into the household bin. Online Bed Store offers a Mattress Collection & Recycling Service, which can be useful if you don't have a suitable vehicle or don't fancy spending the weekend investigating how to transport a king mattress to a recycling facility.

It is a small piece of planning, but one you will appreciate enormously when the replacement arrives.

Mistake #20: Trying to Find the “Best Mattress” Instead of the Best Mattress for You

Search for mattress advice online and you will encounter an endless parade of “best” mattresses.

Best mattress for 2026.

Best mattress for couples.

Best mattress for side sleepers.

Best mattress for back pain.

The problem is that mattresses are unusually resistant to universal rankings because comfort depends so heavily on the person lying on them.

A Heritage Natural 5000 may be a wonderful choice for somebody who likes a softer, naturally filled pocket sprung mattress, while a sleeper seeking significantly more resistance may be far happier on the Hampton Orthopaedic Firm or Extra Firm.

A combination sleeper might begin with the Essentials Cool Touch 1000 in medium, whereas somebody who likes the contouring sensation of foam but still wants medium-firm support might gravitate towards the Stafford 1000 Pocket Memory Sprung Mattress.

Those people aren't disagreeing about which mattress is objectively good.

They are buying for different bodies.

And that is probably the single most useful thing to understand before you start shopping.

A Better Way to Choose Your Next Mattress

Instead of beginning with brands, spring counts or sale prices, begin with yourself.

Think about the position you spend most of the night in, how firm you genuinely like your bed to feel, whether you tend to sleep warm, how much space you and your partner need and whether movement from the other side of the bed disturbs you.

Then establish the practical boundaries: your mattress size, the dimensions of the bed frame, available room space, access for delivery and your budget.

Only after that should you begin comparing constructions.

If you like a more responsive traditional feel, look at pocket sprung mattresses. If you enjoy closer contouring, investigate memory foam or hybrid constructions. If you prefer natural materials, compare the Heritage and other naturally filled options. If you want a very resistant sleeping surface, filter towards firm, extra-firm and ultra-firm models.

Suddenly those 22 mattresses become a much smaller and more manageable shortlist.

Which is exactly what a good buying process should do.

Frequently Asked Questions About Buying a Mattress

What should I look for first when buying a mattress?

Start with your preferred firmness, normal sleeping position and required mattress size. Once those are established, compare construction, materials, temperature preferences, partner disturbance and budget.

Should I buy a soft, medium or firm mattress?

It depends on your sleeping position, body weight and personal preference. Side sleepers often prefer more cushioning, while back and front sleepers may prefer medium-firm or firmer surfaces. There is no firmness level that is universally best.

Is a more expensive mattress always better?

No. Price can reflect more complex construction and premium materials, but the most expensive mattress is not automatically the most comfortable for your body. Suitability matters more than price alone.

Does a higher spring count mean a better mattress?

Not necessarily. Spring count is one element of pocket sprung construction, but mattress firmness and comfort are also influenced by spring tension, fillings, foam layers, pillowtops and overall design.

Should I choose a firm mattress for back pain?

Not automatically. A firmer mattress isn't universally better for people experiencing back discomfort, and individual requirements vary. Persistent or significant pain should be discussed with an appropriate healthcare professional rather than diagnosed through mattress firmness alone.

Is memory foam always soft?

No. Memory foam is a material rather than a firmness rating and can be used within mattresses at different comfort levels. Hybrid and pocket-memory mattresses can provide a contouring foam feel while still offering medium-firm support.

How do I know if my mattress needs replacing?

Look for changes such as visible sagging, an uneven surface, declining support or increasing discomfort. Mattress lifespan varies according to construction, quality and use, although many mattresses are replaced somewhere around the seven-to-ten-year mark.

Can I put a new mattress on an old bed base?

Often, yes, provided the base is compatible, correctly sized and still in good condition. Check for damaged slats, sagging or structural problems first, since an unsuitable base can affect how a new mattress performs.

How long does a new mattress take to settle?

OBS advises that mattress fillings can settle and soften during the first four to six weeks of normal use. Compressed mattresses may also need approximately 24 to 72 hours to reach their full shape after unpacking.

Can I return a mattress after sleeping on it?

Check the retailer's policy before ordering. Under Online Bed Store's current hygiene policy, mattresses cannot be returned once they have been opened, used or slept on unless they are faulty.

The Mattress Specification Isn't Sleeping in Your Bed. You Are.

Perhaps the biggest mattress buying mistake is allowing the shopping process to become more complicated than the purpose of the product.

Spring counts matter. Materials matter. Depth, firmness, construction and price all deserve consideration, particularly when you are buying something you may sleep on for years.

But none of those details exists independently of the person lying on the mattress.

A 5,000-pocket mattress isn't automatically better for you than a 1,000-pocket mattress. Extra firm isn't an upgrade from medium. Memory foam isn't inherently superior to natural fillings, and spending more won't compensate for choosing a mattress that doesn't suit the way you sleep.

The specifications are there to help you understand the mattress, not to make the decision for you.

Start with your body, your sleeping habits and the kind of bed you actually enjoy. Use the technical details to narrow the options, check the practicalities before you order and don't be afraid to ask for guidance when two mattresses look frustratingly similar on screen.

The best mattress isn't necessarily the one with the longest product description, the highest spring count or the firmest surface.

It is the one you stop thinking about once you fall asleep.