Aldi has retained its title as the UK's cheapest supermarket for October, extending an unbroken winning streak to a full 12 months dating back to November 2025, according to the latest price tracking data from consumer champion Which?.
The analysis compared a shopping basket containing 87 everyday grocery essentials across major UK grocers throughout the month. Aldi finished in first place with an average basket total of £154.34, narrowly edging out discount rival Lidl, where the identical basket cost £157.17 with loyalty scheme savings applied (£157.21 without).
Price Gap with Traditional Supermarkets
The findings highlight a substantial pricing divide between the German supermarkets and traditional supermarket chains, even when accounting for members-only loyalty card pricing.
Shoppers using Tesco Clubcard discounts still spent £27.43 more than at Aldi, averaging £181.77 (rising to £187.31 for non-members). Sainsbury's Nectar cardholders paid £182.90 (£191.56 without discounts), while Asda averaged £183.47 and Morrisons reached £186.77.
Premium End of the Market
At the premium end of the market, Ocado registered an average of £202.33, while Waitrose ranked as the most expensive option at £215.87 - a £61.53 premium compared to the identical basket purchased at Aldi.
The results arrive as UK households begin early budgeting for Christmas expenses. While supermarket loyalty schemes continue to dominate promotional marketing strategies, the independent monthly data shows baseline shelf prices at discounters remain difficult for mainstream retailers to undercut.
Aldi's 2026 Performance and Regulatory Changes
Aldi's October win consolidates its commercial performance in 2026, following its previous recognition by Which? as "Cheapest Supermarket of the Year" for 2025 alongside its title of "Best Value Brand of the Year."
In other news for UK grocers, last month the competition watchdog said Aldi and Lidl will face the same rules as other major supermarkets to stop them blocking rival stores from being built. The Competition and Markets Authority (CMA) said including the German discounters in the same land agreement rules as competitors including Tesco and Sainsbury's will help "to ensure customers get the best choice of where to shop".
The watchdog said it will designate Aldi, Lidl GB and Lidl NI as "large grocery retailers" under current industry rules. These rules have applied to Asda, Co-op, Marks and Spencer, Morrisons, Sainsbury's, Tesco and Waitrose since 2010. The rules were introduced to stop large grocery chains from using land contracts to make it harder for rivals to open nearby, particularly through restrictive covenants and exclusivity arrangements.
Aldi is currently the UK's fourth largest supermarket chain, with a 10.5% share of the grocery market, with Lidl the fifth largest, with a 8.6% shares, according to recent data from Worldpanel by Numerator. Aldi and Lidl both stressed the move will not affect their continued store expansion programmes across the UK. It comes two months after the CMA first suggested the discount chains should come under the same rules as their rivals.
