None of what follows is an accusation that supermarkets are doing anything illegal. They're not. What they are doing is using well-established, widely reported pricing and merchandising tactics that are legal, common across the industry, and designed to shape how you perceive value — and once you can see them, you shop differently.
Shrinkflation: the same price, less product
Shrinkflation is the practice of reducing the size or quantity of a product while holding the price steady, or raising the price only slightly. A chocolate bar that used to weigh 200g might now weigh 180g for the same shelf price — the headline number on the price tag hasn't moved, but the price per gram has gone up.
This has been widely reported across categories like crisps, biscuits, toiletries and confectionery in recent years. It's a rational response by manufacturers to rising input costs that doesn't require an unpopular headline price rise, but it does mean the price tag alone tells you less than it used to.
Loyalty card pricing and the inflated "was" price
Loyalty schemes like Tesco Clubcard Prices and Sainsbury's Nectar Prices offer genuine discounts to cardholders on a rotating set of products. The saving itself is usually real — you do pay less with the card than without it on those items.
Where it gets murkier is the comparison being shown. The non-member "was" price displayed next to the Clubcard or Nectar price is sometimes set at a level that few shoppers would have paid anyway, which makes the loyalty discount look bigger than the actual saving versus a competitor's everyday price. This has drawn scrutiny from consumer groups and regulators. The practical takeaway: treat the loyalty price as the number that matters, and ignore the framing around it — then compare that loyalty price against other shops using unit pricing.
Unit pricing is the only fair comparison
The single most useful piece of information on any supermarket shelf is the small unit price — pounds per 100g, per 100ml, or per item — printed below or beside the headline price. It's mandated specifically so shoppers can compare products of different pack sizes fairly.
Headline prices are easy to manipulate through pack size changes, multi-buy deals and promotional framing. Unit price is much harder to dress up, because it strips all of that away and reduces everything to a single comparable number. If you take one habit from this article, make it glancing at the unit price before the headline price.
Own-brand versus branded: where the real savings live
Supermarket own-brand ranges, especially the entry-level tiers, are consistently among the cheapest way to buy staple goods, and in many cases are manufactured to a similar specification as branded equivalents. The middle and premium own-brand tiers narrow the savings considerably and sometimes aren't far off branded prices at all.
Branded goods are also where promotional pricing tends to be most aggressive and most confusing — multi-buy offers, "was/now" pricing, and limited-time deals cluster heavily on branded products because there's more margin to play with. If you're shopping to a tight budget, the entry-level own-brand tier is usually the most reliably cheap option without needing to track promotions at all.
Why head-to-head supermarket comparisons are unreliable
You'll see regular headlines claiming one supermarket is cheaper than another based on a fixed basket of goods. These comparisons are real, but they're sensitive to exactly which items are chosen. A basket weighted towards branded goods will favour a different supermarket than one weighted towards own-brand staples or fresh produce, because pricing strategy varies category by category, not just chain by chain.
The only basket comparison that means anything is your own. If you genuinely want to know who's cheapest for you, price your actual regular shop across two or three supermarkets using their apps or websites, rather than trusting a generic headline comparison.
Multi-buy and promotional framing
"3 for £5" and "was £4, now £3" style promotions are another area worth a second glance. These offers are usually genuine in the sense that the promotional price is real, but the comparison price they're framed against isn't always the price most shoppers were actually paying beforehand — sometimes it's a price the product was only briefly at, or one that applied to a different pack size. The promotion itself can be a good deal; the framing around how big a saving it represents is the part to treat with a little scepticism.
It's also worth asking whether you actually need three of something before a multi-buy offer talks you into it. Buying more than you need at a slightly better unit price is only a saving if you use what you've bought before it goes off or goes stale — otherwise the "saving" is just food waste with a discount attached.
Checkout placement and basket psychology
Pricing tactics aren't only about the number on the tag. Supermarkets are deliberately laid out so that higher-margin impulse items — sweets, magazines, last-minute add-ons — sit at the checkout and at eye level along main aisles, while staple items like milk, bread and eggs are often positioned further into the store. None of this changes the price of anything, but it does shape how much ends up in your basket beyond what you planned to buy.
Shopping with a list, and resisting the urge to wander the full store "just to see," is a low-effort way to sidestep this entirely. It won't change a single price tag, but it changes your total spend more reliably than most pricing-specific tactics on this page.
What regulators and consumer groups have said
UK consumer and competition bodies have looked at pricing practices like shrinkflation and promotional discount framing in recent years, generally pushing for clearer unit pricing and more honest reference prices in promotions rather than banning the underlying practices outright. The direction of travel has been towards better information for shoppers — which is exactly why unit pricing has become more prominent and more reliable as a comparison tool than it used to be.
My take
Supermarkets aren't doing anything underhand by industry standards — this is how retail pricing has worked for decades, and most of it is well documented and openly discussed by the industry itself. The shift you need to make is simply where you look: away from the big number on the shelf edge, and onto the unit price below it. That one habit beats almost every pricing tactic on this list at once.