The Competition and Markets Authority (CMA) has called for reforms on unit pricing legislation, saying that retailers must comply to help shoppers compare prices easily.

Unit pricing – the price per 100g or 100ml, for example – helps shoppers compare the prices of different products and make informed decisions about what to buy. This is particularly important during the cost-of-living crisis as grocery inflation has hit historical highs.

The CMA review looked at 11 supermarkets and seven variety retailers (stores that sell homeware and household goods with a more limited range of groceries) that operate in the UK.

It found compliance concerns with the Price Marking Order (PMO) among all those it reviewed. However for some retailers these were relatively minor. The CMA has identified that compliance is worse among some variety retailers.

Some of the problems stem from the unit pricing rules themselves, which allow unhelpful inconsistencies in retailers’ practices and leave too much scope for interpretation. As a result, shoppers may be finding it hard to spot and compare the best deals.

‘Hard to compare like-for-like deals’

The CMA’s concerns cover four areas: consistency, transparency, legibility and promotions.

It found that different measurements are being used for similar types of products, making it hard for consumers to compare deals on a like-for-like basis. For example, tea bags being priced per 100 grams for some products and others being unit priced per each tea bag.

Researchers also found incorrectly calculated unit pricing information and unit pricing information being difficult to read. Some retailers failed to display unit prices for any products on promotion.

Sarah Cardell, CEO of the CMA said: “With so many people struggling to feed their families, it’s vital that we do everything we can to make sure people find the best prices easily. We’ve found that not all retailers are displaying prices as clearly as they should, which could be hampering people’s ability to compare product prices.

“We’re writing to these retailers and warning them to make the necessary changes or risk facing enforcement action. The law itself needs to be tightened here, so we are also calling on the government to bring in reforms.”

Supermarkets must ‘do the right thing’

Sue Davies, Which? head of food policy said: “Which? has repeatedly exposed inconsistent and confusing supermarket pricing, which could make it difficult for shoppers to easily work out which products offer the best value, so it’s positive to see the Competition and Markets Authority calling for immediate action from the supermarkets on this issue.

“The supermarkets must finally do the right thing by their customers and urgently act on the areas highlighted by the regulator. This includes the need to put unit pricing on promotions, such as on loyalty card offers and multi-buys, and make unit pricing clearer and more consistent.”