A law change governing supermarket price labels is now in force (Image: Getty)
Aldi, Tesco, Asda, Morrisons, Sainsbury’s and all other major supermarkets will be made to follow a law change that was introduced in April.
Every major supermarket must comply with new retail rules from the government which dictate how items must be labelled on shelves under Price Marking Order reforms.
The law change governs the way items’ prices are displayed, with a particular focus on making it easier for customers to compare two or more products and work out which is the cheapest.
This is because the lowest price is not always the cheapest, as items can have different pack sizes, different weights or different liquid volumes and in recent years, manufacturers have increasingly turned to cutting item sizes or volumes down while keeping the price the same (or even raising it as well) in a practice which has come to be called ‘shrinkflation’.
Last year, the Express reported how Asda was selling items in contravention of the legislation for several weeks, until it updated its labels on shelves and issued an apology following our reporting.
Tesco will also be impacted by the new law (Image: Getty)
The Price Marking Order 2004 has, as of April 2026, been updated to change the rules around unit pricing further.
The changes have standardised unit rates, outlawing the practice of mixing two different measurements on the same shelf – for example, some retailers used to price one product in KG and another in grams, making comparisons more difficult. From now, all price labels must use KG, litres, metres, square metres or cubic metres.
Loyalty schemes, such as the Tesco Clubcard and the Sainsbury’s Nectar Card, are also now governed by the new rules, including making it illegal to give ‘undue prominence’ to loyalty prices on shelf labels.
Solicitors Herrington Carmichael explains: “Where a product is offered at more than one price for example, a standard price and a loyalty price, traders must display both selling prices together and, where unit pricing applies, show the corresponding unit price for each. Traders should state the eligibility conditions clearly and next to the prices, for example, that the loyalty price is available with a valid loyalty card, and ensure neither price is given undue prominence.”
The law has also been extended to include more products.
The firm adds: “Obligations extend to more packaged goods including cereals, pasta, dried fruits, detergents, cleaning products and cosmetics. This is intended to support like for like comparisons on a wider range of everyday items.”
The rules do not apply to smaller shops which have a floor space of less than 280msq, so don’t apply to corner shops and convenience stores.
The law also will allow for blanket reductions, such as “20% off all paint” without forcing retailers to change every label.
Herrington Carmichael adds: “The Price Marking Order 2004 is designed to ensure consumers can make informed purchasing decisions by requiring clear and transparent price information. This is particularly important where products are sold in different sizes, or where promotions, discounts, and loyalty pricing apply.
“…The purpose behind the recent Price Marking Order reforms is to strengthen this transparency. The changes expand the scope of unit pricing to more product categories, clarify how selling and unit prices should be displayed where multiple prices apply, and introduce updated definitions, including a new requirement to display deposits separately.”