What the data show
- According to the consumer‑group Which?, for a basket of 76 everyday grocery items in July 2025, rival discounter Lidl came in cheaper at £128.40, compared to Aldi’s £129.25. (Grocery Gazette)
- More broadly, reports note that Aldi had held the title of cheapest supermarket for nearly 20 months before this shift. (JOE.co.uk)
- Some coverage adds nuance: the ranking can depend on loyalty schemes, basket size and mix of items. For example, Lidl’s loyalty programme “Lidl Plus” helped boost its position. (NationalWorld)
Why this matters
- For shoppers: the change means that the “go‑to cheapest” label for Aldi is no longer guaranteed — price‑conscious shoppers may need to compare more actively rather than assume Aldi is always lowest.
- For Aldi: losing the title could affect marketing, brand perception and competitive positioning. The “cheapest” badge was a strong differentiator.
- For Lidl (and potentially other chains): this is a strategic win — they can emphasise value, attract more customers, and potentially invest further in price leadership or margin management.
- For the grocery market: this signals intense competitive pressure among discounters and value chains, especially at a time of inflation, rising food costs and cost‑of‑living stress.
Key factors behind the shift
- Margin and pricing pressure: With inflation in grocery items (fresh produce, meat, etc) still elevated, margins are under strain for all chains — pushing them to optimise cost, supplier deals and pricing.
- Loyalty schemes & pricing strategy: Lidl’s use of its “Lidl Plus” discount scheme and targeted pricing may have given it a small edge. (E.g., savings on certain items for loyalty members.) (Derbyshire Times)
- Basket methodology: These rankings hinge on a defined basket (76 items, popular brands + own‑brand) and monthly data. Small differences can change leadership. For example, Lidl beat by just ~85p in that July basket. (Derbyshire Times)
- Competitive response from Aldi: Aldi may need to review its cost base, product mix, promotional strategy or store operations to regain leadership or defend value perception.
- Market segmentation / store formats: The broader supermarket landscape shows variation — for “bigger trolleys” (larger purchase volumes) the cheapest retailer may differ (for example, other chains rather than Aldi or Lidl) as the basket of branded goods and size matters. (Grocery Gazette)
Strategic commentary & implications
For Aldi
- Brand risk: Losing the “cheapest” tag can weaken Aldi’s core value proposition — they may need to emphasise other strengths (own‑brand quality, store experience, convenience) rather than just lowest price.
- Pricing strategy: They might re‑emphasise deeper discounts, price matching, promotional offers, or sharper differentiation of own‑brand.
- Operational cost control: Given tighter margins, Aldi must ensure efficiency (supply chain, store operations, shrinkage, logistics) to maintain low cost base without compromising quality.
- Customer communications: Keeping customers aware that “we still deliver exceptional value” becomes more important; perception can lag data.
For Lidl
- Opportunity to solidify advantage: Having taken the lead, Lidl can invest to maintain or extend the gap — e.g., enhance loyalty scheme benefits, expand store footprint, leverage value messaging.
- Watch out for margin squeeze: With value leadership, maintaining low price points while managing inflation and supply‑chain cost increases is challenging.
- Marketing narrative: Lidl can use this win in consumer messaging (“now UK’s cheapest supermarket”) to attract more budget‑conscious shoppers.
For shoppers & market
- Active shopping behaviour: Price leadership is no longer static — shoppers may benefit from comparing baskets and looking at loyalty schemes rather than assuming one retailer always best.
- Sector pressure: Other supermarkets (mid‑market and premium) will feel increased pressure to compete on price or value‑added services (loyalty, convenience, digital).
- Inflation context: The shift comes in the midst of rising grocery inflation (~5.2% year‑on‑year for food & non‑alcoholic drinks in July) which heightens the importance of value positioning. (Derbyshire Times)
What to watch next
- Monthly basket data: Whether Aldi can reclaim the title, or whether Lidl further extends its lead in subsequent months.
- Broader basket sizes: How these rankings change when bigger or more branded item baskets are used rather than standard 76‑item list.
- Loyalty & digital offers: Whether loyalty programmes (Lidl Plus, Aldi’s own promotions) become more influential in determining perceived value.
- Store network / format changes: Whether either chain changes store formats, opens more locations, or invests in technologies to lower cost/offer more value.
- Quality and service: Value leadership may be challenged not just on price but also on quality, availability, service — are customers satisfied with what they get? Some anecdotal commentary notes quality concerns. (Reddit)
In summary: Aldi’s long‑term leadership as the UK’s cheapest supermarket has been dethroned by Lidl, albeit by a very narrow margin. While this may seem like a small shift on paper (85p difference in a standard basket), in the highly competitive UK grocery market and under current cost pressures, the change is meaningful for brand positioning, shopper behaviour and competitive strategy.
Here are case‑studies + commentary on the story of Aldi losing the title of the UK’s cheapest supermarket, what prompted the change, what it means — and lessons for the grocery retail market.
Case Study 1: Aldi’s Long‑Run Price Leadership
Background & evidence
- For much of recent years, Aldi held the crown as the UK’s cheapest supermarket. For example, a study for 2024 by Which? found Aldi to be the cheapest in all 12 months (for a 56‑item basket) at £100.29 on average, compared with Lidl at about £101.48. (The Standard)
- In earlier years (2022, 2023) Aldi also featured at the top of price‑comparisons: e.g., a 47‑item basket in 2022 cost £74.23 at Aldi, compared with higher figures at other supermarkets. (ALDI UK Press Office)
- Aldi used these results in its public communications (press releases) to emphasise its value proposition. For example: “We will continue to support customers by consistently offering them great quality products at the lowest possible prices.” (ALDI UK Press Office)
Key strategic drivers behind Aldi’s leadership
- Cost structure: Aldi’s lean store formats, limited SKUs, strong own‑brand penetration helped keep prices low.
- Value messaging: For budget‑conscious consumers (especially amid cost‑of‑living pressures) Aldi’s brand of “lowest price” was attractive.
- Focus on everyday staples: The baskets used by price comparisons emphasised staples (bread, milk, basic branded items + own label) – categories where discounters tend to excel.
Case Study 2: Change of Title – Lidl Overtakes Aldi
What happened
- In July 2025, Which? compared 76 popular grocery items across major supermarkets and found that Lidl beat Aldi, ending Aldi’s 20‑month run at the top. Specifically: Lidl’s basket cost £128.40 without its loyalty card and £128 with it; Aldi’s was £129.25. (Retail Gazette)
- Coverage noted that Aldi’s hold was for nearly two years and that the margin of difference this time was narrow (less than £1) but meaningful from a marketing/positioning standpoint. (The Standard)
Why the shift? Possible causes
- Competitive pressure: Lidl possibly sharpened its value offering, benefiting from loyalty scheme “Lidl Plus” and aggressive pricing or promotions.
- Cost inflation: Food inflation at ~5.2% in July 2025 (fresh meat, chocolate, spreads) increased pressure on all grocers; even discounters may have been pushed to adjust price assumptions. (Retail Gazette)
- Basket / methodology effects: The basket used was 76 items—changes in list, SKUs, loyalty pricing could shift outcomes.
- Marketing and brand perception: As consumers become more price‑sensitive, slight edges in pricing matter more for perception.
Strategic Commentary & Lessons
- Even small margins matter
- The difference between Lidl and Aldi was under £1 on the basket (~£128 vs ~£129). That is modest on absolute terms but large for brand differentiation and consumer perception.
- Being “cheapest” is a strong marketing asset; losing it shifts how shoppers view you, especially the value‑conscious segment.
- Value leadership is volatile in inflationary times
- In a high inflation environment, keeping cost and price margins stable is harder. Discounters must manage input cost inflation, supply chain, promotions, store network.
- Even if you have historically had the lowest price, competitors catching up or overtaking is a real risk.
- Brand positioning & messaging must evolve
- For Aldi: losing the title means they may need to emphasise other strengths (quality, service, convenience, own‑brand innovation) beyond just “cheapest”.
- For Lidl: winning the title offers a marketing opportunity (“Now UK’s cheapest supermarket”) to attract more value‑driven consumers and build loyalty.
- Loyalty schemes, basket size & mix matter
- The methodology shows that loyalty card prices and the item‑mix drive outcomes. Retailers must examine not just headline price but effective price after loyalty, promos, and basket composition.
- Larger baskets (with more branded SKUs) show different results: for instance, in a 192‑item basket, Aldi/Lidl were excluded because they did not stock all items and full‑price supermarket chains dominated. (Retail Gazette)
- Competitive dynamics in grocery sector
- This shift signals intensifying competition among discounters and value chains. Other supermarkets (traditional ones) may also respond by reinforcing value, simplifying range, reducing cost.
- For consumers: more switching behaviour, more “value hacks”, more comparison shopping.
Implications & What to Watch
- Will Aldi regain the title? The press release from Aldi on 4 September 2025 claimed they had taken back the crown for August (basket of 75 items) at £127.92 versus Lidl’s £128.35. (ALDI UK Press Office) This indicates the title may flip frequently, not permanently lost.
- Watch for price war effects: If one discounter pushes aggressively, others may follow, potentially compressing margins across the sector.
- Consumer behaviour: Are shoppers switching stores because of this difference? Research in 2024 showed 37% of shoppers changed their regular supermarket and 45% cut back on treats. (The Independent)
- Loyalty programmes & digital apps: As Lidl’s loyalty card helped improve its position, expect more value from such tools and more emphasis on “effective price” rather than list price.
Summary
The story of Aldi losing the “cheapest supermarket” crown (even if temporarily) is more than a single data point. It shows how value leadership in UK grocery is highly competitive, subject to small price differences, and influenced by basket methodology, inflation pressure, and loyalty programmes. For Aldi, the shift means a wake‑up call to protect its value edge or pivot to other differentiators. For the broader sector, the dynamic underlines that in tight economic times consumers will seek the cheapest option—but retailers must execute consistently to maintain that claim.