"Use By" vs "Best Before": What's Actually Safe to Eat

In the UK, roughly one loaf of bread in three is thrown out because of its best-before date. That’s WRAP’s figure, and the striking part is that the best-before date on bread has nothing to do with safety at all. It’s a bakery’s estimate of when a loaf stops being at its nicest. People are binning perfectly good food because of a number printed on a bag.

At the same time, some date labels genuinely are safety limits, and ignoring those is how people get seriously ill.

The problem is that the two look identical — small print, same font, same corner of the packet — while meaning completely different things. And which one means what depends on which country you’re in.

Here’s the actual rule set.

The core distinction

There are two categories of date label anywhere in the world, whatever they’re called locally:

Quality dates tell you when the manufacturer thinks the product stops being at its best. Texture, flavour, colour, crunch. Food past a quality date is legal to sell in most places, legal to eat, and usually completely fine. This is what “best before,” “best if used by,” and “sell by” mean.

Safety dates tell you when a food becomes genuinely risky, because it supports the growth of pathogens that don’t announce themselves by smell or taste. This is what “use by” means in the UK and EU.

Almost all food waste caused by date labels comes from treating quality dates as safety dates.

In the UK: “use by” is a hard line, “best before” isn’t

UK rules are the clearer of the two systems, and the Food Standards Agency is unambiguous about it.

“Use by” = safety. The FSA’s guidance is blunt: never eat food after the use-by date, even if it looks and smells fine. This applies to the foods that carry it — fresh meat and poultry, fish, ready meals, chilled ready-to-eat foods, some dairy. The reason is that the organisms of concern here, particularly Listeria monocytogenes, grow at fridge temperatures and produce no smell, no slime and no off taste. Your senses are not a detector for this. Someone in a higher-risk group — pregnant, elderly, immunocompromised — can become seriously unwell from food that seemed perfect.

One crucial detail people miss: you can freeze or cook food right up to midnight on the use-by date. Freezing pauses the clock. Chicken with a use-by date of today, frozen today, is fine — and when you defrost it, use it within 24 hours. This single fact rescues an enormous amount of food.

“Best before” = quality. Applies to the durable stuff: tinned goods, dried pasta, rice, biscuits, crisps, frozen food, and most bread. Food past best before is legal to sell and safe to eat if it’s been stored properly. It might be staler, softer or less vivid. Use your judgement.

You’ll also see “display until” or “sell by.” These are for shop staff, for stock rotation. They mean nothing to you as a shopper. Ignore them entirely.

There’s a live policy shift here too: WRAP has been pushing retailers to remove date labels from uncut fresh fruit and vegetables, on the basis that people can see whether an apple is fine, and the label just causes premature binning. Several UK supermarkets have done it, and many have also moved milk from “use by” to “best before” specifically to encourage the sniff test.

In the US: almost nothing on the packet is a safety date

The US system is far looser, and this surprises people.

With one exception — infant formula — there is no federal law requiring date labels on food, and the dates that do appear are quality indicators, not safety limits. The USDA’s Food Safety and Inspection Service states that dates indicate quality, and that food is generally safe to consume past the printed date if it’s been stored properly and shows no signs of spoilage.

FSIS has been trying to reduce the chaos by encouraging manufacturers to standardise on “Best if Used By” for quality. But you’ll still encounter:

• Sell by — a stock-rotation instruction for the retailer. Not for you.
• Best if used by / Best by — quality.
• Use by — in the US, usually still quality, except on infant formula, where it’s a genuine limit and should be respected absolutely.
• Freeze by — when to freeze it for best quality, not a safety limit.

Two states have started fixing this. California passed the first law standardising labels into “BEST if Used By” for quality and “USE By” for safety, and New York has passed comparable legislation. Other states have similar bills in progress. Until those are widespread, a US shopper should assume a date is about quality unless it’s infant formula.

The practical consequence: American shoppers are throwing away far more food to date confusion than they need to, and the USDA is actively telling them not to.

US vs UK at a glance

Label	UK meaning	US meaning
Use by	Legal safety limit. Do not eat after. Freeze or cook up to midnight on the date.	Usually quality. Genuine safety limit only on infant formula.
Best before / Best if used by	Quality only. Safe after, if stored properly.	Quality only. Safe after, if stored properly.
Sell by / Display until	For shop staff. Ignore.	For shop staff. Ignore.
Legal requirement?	Yes — “use by” is required on high-risk foods.	No federal requirement except infant formula. Varies by state.

If you’ve moved between the two countries, this table is the thing to internalise. A British shopper treating a US “use by” as a legal wall will waste food; an American treating a British one as a suggestion is taking a real risk.

How to judge food yourself, by category

Once a date is off the table as your decision-maker, you need actual assessment skills. These are category-specific.

Milk. Smell it. Sour milk announces itself unmistakably and it isn’t dangerous, just unpleasant. Pasteurised milk is typically fine several days past a best-before date if it’s been kept at the back of the fridge rather than the door. If it’s thickened, lumpy or yellowing, bin it.

Hard cheese. Mould on hard cheese — cheddar, parmesan, gouda — can be cut off. Take a generous inch around and below the spot. The dense structure stops mould filaments spreading far.

Soft cheese, yoghurt, sour cream, cottage cheese. Different rule: mould on soft, high-moisture foods means the whole thing goes. You can’t cut out what you can’t see, and the moisture lets it spread invisibly. (Blue cheeses and bloomy rinds are a separate case — those moulds are meant to be there.)

Eggs. The float test is reliable. In a bowl of water: sinks and lies flat, fresh; sinks and stands on end, older but fine, use it cooked through; floats, bin it. Eggs are often good for weeks past their date.

Raw meat and poultry. In the UK this carries a use-by date and you should respect it. In the US, judge by condition: slimy or tacky surface, grey-green discolouration throughout, or a sour or ammonia smell means bin it. Some surface darkening on beef is just oxidation and is fine.

Fish. Should smell of the sea, not of ammonia. Flesh should be firm and spring back. Fish is the least forgiving thing in your fridge — when in doubt, bin it.

Bread. Visible mould means the whole loaf goes, including the slices that look clean — mould in soft bread spreads through the crumb well beyond what you can see. Stale but mould-free bread is not waste: it’s croutons, breadcrumbs, French toast, panzanella, bread-and-butter pudding.

Tinned food. Extremely long-lived, often years past best before. The things that matter are physical: a bulging, badly dented at the seam, leaking or rusted-through tin goes in the bin unopened, regardless of date. Once open, decant into a container — the tin isn’t for storage.

Dried goods. Pasta, rice, lentils, flour, spices. Best-before dates here are near-meaningless. Flour can go rancid — smell it, it’ll be obvious. Spices lose potency but don’t become unsafe. Check for pantry moths.

Fresh produce. Look at it. A soft spot on an apple gets cut out. A slimy leaf gets removed. Limp carrots and celery revive in cold water for an hour. Sprouting potatoes are fine — knock the sprouts off — but green ones should be discarded.

Leftovers. This is the category where dates don’t exist and people improvise badly. Cooked food keeps 3–4 days in the fridge. Cool it quickly, within about two hours of cooking, and refrigerate. Reheat until steaming hot throughout. Rice deserves special caution: cool it fast, refrigerate within an hour, eat within a day, and don’t reheat more than once.

Where the sniff test isn’t valid

Worth being direct about, because “trust your senses” gets repeated as universal advice and it isn’t.

Your senses reliably detect spoilage organisms — the ones that make food smell bad. They do not reliably detect pathogenic organisms. Listeria in particular grows at fridge temperature, in ready-to-eat chilled foods, with no sensory signal at all.

So the sniff test is a good tool for: milk, bread, produce, dried goods, hard cheese, leftovers within the safe window.

It is not a substitute for the use-by date on: chilled ready meals, cooked sliced meats, smoked fish, pâté, soft ripened cheeses, pre-prepared salads and sandwiches. And if anyone in your household is pregnant, elderly, very young or immunocompromised, treat those dates as absolute.

Make the dates matter less

The real solution isn’t better date-reading. It’s not reaching the date in the first place.

• Check your fridge temperature. It should be at or below 5°C / 40°F. A surprising proportion of home fridges run warmer, which quietly shortens the life of everything inside. A £5 fridge thermometer is the highest-return purchase in this entire article.
• Use the door for the durable stuff only. The door is the warmest part and swings several degrees every time you open it. Condiments and juice belong there. Milk and eggs don’t, despite the moulded egg holder.
• Know your fridge’s cold spot. In most fridges it’s the bottom shelf. Raw meat goes there — coldest, and nothing can drip onto food below it.
• Freeze on the day, not the date. The most common mistake is intending to freeze something “before it goes off” and then missing the window. Freeze the half loaf on shopping day, not on day four.
• Keep the about-to-expire things visible. A single “eat me first” box at eye level in the fridge does more than any amount of date literacy.

The short version

In the UK, “use by” is a genuine safety limit and “best before” is a quality guess. In the US, essentially every date except on infant formula is a quality guess. Sell-by dates are for shops. Freezing stops the clock. And your nose is a good instrument for spoilage and a poor one for pathogens.

Internalise that and you’ll stop throwing away food that was fine — which, for the average household, is most of what ends up in the bin.

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This article is general guidance, not medical advice. For authoritative detail, see the Food Standards Agency (UK) and USDA FSIS (US).