Tesco Overtakes Asda as UK's Cheapest Big Shop Supermarket in Which? Study

Britain's largest supermarket chain, Tesco, has emerged as the most affordable option for a major grocery haul in January, according to fresh analysis from consumer champion Which?. This marks a significant shift in the competitive landscape, with Tesco toppling its long-standing rival Asda from the top spot for the first time in over a year.

Price Comparison Reveals Narrow Margin

The consumer group conducted a comprehensive price comparison across 228 popular grocery products, representing a typical large shopping trip. Tesco secured the cheapest total bill of £588.96, but this figure is exclusively available to customers who utilise special prices through the retailer's Clubcard loyalty scheme. Asda, which had held the title since December 2024, was a mere £1.45 more expensive, with a basket cost of £590.41.

However, a crucial caveat exists. Which? emphasised that while Asda's pricing is accessible to all shoppers, Tesco's Clubcard discounts are not universally available. Shoppers without a Clubcard, including those under the age of 18, would face a substantially higher bill of £641.09 at Tesco—a staggering £52.13 more than the discounted rate and significantly above Asda's standard price.

Asda's Ongoing Struggles and Strategic Response

This price defeat comes amid a challenging period for Asda. The Leeds-based grocer has been contending with declining sales following its debt-fuelled acquisition in 2021 by billionaire brothers Mohsin and Zuber Issa and private equity firm TDR Capital, which now holds controlling interest. In a bid to reverse its fortunes, Asda reinstated veteran executive Allan Leighton as its executive chairman in 2024, hoping to replicate the turnaround success he engineered in the 1990s.

An Asda spokesperson defended the chain's value proposition, stating: "Asda was the lowest-priced supermarket every month in 2025 on the Which? big trolley comparison, and £50 cheaper in January on a like-for-like basket without loyalty pricing. Asda remains the best-value supermarket for the big family shop with prices available to all."

Discounters Lead on Smaller Baskets

For a more modest shop of 89 items, which includes a mix of branded goods like Birds Eye Peas and Hovis bread alongside own-label products, the discount supermarkets reign supreme. Aldi was crowned the cheapest overall, with an average cost of £164.74. Its fellow discounter, Lidl, was close behind at £166.53, or £166.33 for customers using its loyalty discount.

In contrast, Waitrose was the most expensive option for both shopping baskets. The upmarket chain's large shop averaged £679.20—£90.24 pricier than Tesco with a Clubcard—while its smaller basket totalled £221.53, which is £56.79 more than Aldi.

Expert Advice for Cost-Conscious Shoppers

Reena Sewraz, Which? Retail Editor, commented on the findings: "While Aldi is the cheapest supermarket this month, the ongoing price competition among the discounters means Lidl also remains a strong money-saving choice for many shoppers, according to our latest price analysis. For those who prefer a wider range of branded products, shopping at Tesco with a Clubcard can offer good value."

She added a note of caution regarding accessibility: "However, it's worth noting that Tesco's loyalty-linked discounts aren't accessible to everyone. Tesco must do more to ensure under-18s and other groups who may not be eligible for the Clubcard don't miss out on those savings. With food bills still a major concern for many households, it really does pay to shop around—choosing one supermarket over another could save shoppers hundreds of pounds over the course of a year."

The Which? big shop analysis specifically excludes Aldi and Lidl from the primary 228-item comparison due to their more limited product ranges, focusing instead on the traditional full-range supermarkets.