Paying the price – Supermarkets confusing shoppers with unclear product pricing amid cost of living crisis, Which? finds

Which? is calling on supermarkets to make pricing clearer as it finds confusing pricing practices are making it difficult for shoppers struggling amid the cost of living crisis to work out which food and drink products are the best value.

Some versions of the same product can cost up to three and a half times more (346%) per unit at the same supermarket, the consumer champion has found, highlighting why clear and consistent unit pricing is vital for helping consumers to find the cheapest option.

In a survey, Which? found that seven in 10 people (72%) could not work out the cheapest item in a range of real-life examples from supermarkets.

As part of the investigation, Which? tracked the prices of 10 popular groceries including Coca-Cola, own-label semi-skimmed milk, Dairy Milk chocolate, Nescafe instant coffee and Weetabix at the ‘Big Four’ supermarkets (Asda, Morrisons, Sainsburys and Tesco) for three months.

In one example, up to 17 different-sized versions of Coca-Cola were available with prices varying between 11p and 50p per 100ml at Tesco. That’s 346 per cent more for a shopper who buys four 250ml glass bottles (£5) than one who picks up a 1.5 litre bottle instead (£1.68).

Which? also found that the price per 100ml of own-brand semi skimmed milk varied between 6p and 13p at Morrisons – that’s 133 per cent more for a shopper choosing a 500ml bottle (65p) than one picking a 2.27-litre one (£1.27). 

Researchers from Which? visited branches of nine major supermarket stores (Aldi, Asda, Iceland, Lidl, M&S, Morrisons, Sainsbury’s, Tesco and Waitrose) to see how unit pricing is working in practice and found a multitude of problems.

The consumer champion found fruit and vegetables such as pears and tomatoes which, depending on the pack size or variety, were given a price each, per pack, or per 1 Kg – making it difficult to compare prices.

There was also confusing terminology; such as for peppers at Lidl, which were priced both per ‘piece’ and ‘each’. Meanwhile at M&S, ‘each’ was used to mean both a pack of four pears and also a single pear.

There were also many times when the price per unit was clearly displayed but did not apply to a special offer, promotion or other reduction on price. 

There were numerous examples of pricing that was hard to read or missing entirely – such as for a pack of tomatoes in Tesco, Penguin bars in Waitrose, some soft fruit in Morrisons and vine tomatoes in M&S. 

The findings show that there also remains poor quality control in some supermarkets at the way pricing is displayed

Which? Also found that there are also big differences with how supermarkets present and use unit pricing online, particularly for promotions. 

When Which? looked at nine major supermarket websites (Aldi, Amazon Fresh, Asda, Iceland, Morrisons, Ocado, Sainsbury’s, Tesco and Waitrose) it found all displayed unit pricing for standard-priced items and for discounted items. But researchers were unable to find unit pricing for multibuys at any of the supermarkets, although not all the discounters sell them. 

When Which? looked at Tesco, the supermarket with the biggest market share, it found most Tesco discounts are now offered through Clubcard Prices, which don’t show unit pricing. That means most discounts in Tesco are difficult to compare with other similar products.

Displaying prices of goods and therefore unit prices is governed by the Price Marking Order 2004 but the legislation specifies a range of different units that can be used depending on the product type so there can be confusion for shoppers.

Which? has campaigned on the issue of unclear pricing before, culminating in a super-complaint to the Competition and Markets Authority in 2015. That led to a series of recommendations to improve unit pricing in supermarkets – but the legislation itself was not changed.

Which? believes clear, fair and transparent pricing is now key to helping shoppers through the current cost of living crisis and is calling on supermarkets to urgently do more by making unit pricing more prominent, legible and consistent – as well as by displaying it on their promotional offers.


Sue Davies, Which? Head of Food Policy, said: 

“At a time when food prices are a huge concern, unit pricing can be a useful tool for shoppers to compare and choose the cheapest groceries but unclear supermarket pricing means the vast majority of people are left struggling to find the best deal.

“Small savings can add up and make a big difference but unless supermarkets make unit pricing much more prominent, legible and consistent – as well as displaying it on their promotional offers – people will continue to risk missing out on getting the best value.”



Notes to editors:

Video – shows how much people struggle to spot the best value item is a series of vox pops-


In June 2022, Which? surveyed a representative sample of 2,000 UK adults.

Which? also carried out a price analysis on 10 popular food items across the ‘Big Four’ supermarkets (Asda, Morrisons, Sainsbury’s and Tesco) from1 March to 31 May 2022.

To see how unit prices work, Which? researchers visited nine supermarkets (Aldi, Asda, Iceland, Lidl, M&S, Morrisons, Sainsbury’s, Tesco and Waitrose) and looked at nine websites (Aldi, Amazon Fresh, Asda, Iceland, Morrisons, Ocado, Sainsbury’s, Tesco and Waitrose) in June 2022.

More information on The Price Marking Order 2004:





Which? approached Aldi, Amazon Fresh, Asda, Iceland, Lidl, M&S, Morrisons, Ocado, Sainsbury’s, Tesco and Waitrose with the findings. Only Lidl and Waitrose provided Which? with an official response.


Lidl: A Lidl spokesperson said: “We always endeavour to ensure that pricing information is as clear as possible for our customers so that they can make informed purchasing decisions.”


Waitrose: A Waitrose spokesperson said: “We regularly review all our products to ensure our unit pricing is clear and consistent, so that customers can compare prices and save money. Our Partners are always on hand to assist customers with any pricing queries.” 

Advice to consumers: 


1) Calculate the overall volume of the product (if it’s a multipack, you may need to multiply the number of items by the volume of each to get the overall total)

2) Then take the price and divide by the volume


Tip: Make sure you keep the units consistent – eg ml or litres and pence or pounds.




About Which?


Which? is the UK’s consumer champion, here to make life simpler, fairer and safer for everyone. Our research gets to the heart of consumer issues, our advice is impartial, and our rigorous product tests lead to expert recommendations. We’re the independent consumer voice that influences politicians and lawmakers, investigates, holds businesses to account and makes change happen. As an organisation we’re not for profit and all for making consumers more powerful.


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