Your Supermarket Has Two Prices. Which One Is the Deal?

Supermarket loyalty prices can offer genuine discounts, but a genuine discount is not the same as the lowest available price. The saving shown on a shelf usually compares two prices for one product in one shop. Your actual decision may involve another shop, a different product, a different pack size or whether you need the item at all.

That distinction makes sense of two apparently conflicting experiences. You can save money by scanning a loyalty card and still find the same product cheaper elsewhere. You can also buy a discounted product and spend more overall because the offer changed what went into your basket.

The useful question is therefore: cheaper than which realistic alternative?

What the competition regulator actually found

In its 2024 review, the UK's Competition and Markets Authority examined loyalty pricing at five supermarkets. Its executive summary reported that 92% of roughly 50,000 products it analysed offered genuine savings against the usual price. Average discounts at the supermarkets ranged from 17% to 25%.

The same review included a separate comparison of 429 branded products, finding 61 available for less at another retailer. These are historical findings from the study, not a live ranking of today's cheapest supermarket.

Together, they support a precise conclusion: many discounts were real relative to the retailer's usual price, while some loyalty offers could still be beaten elsewhere. Neither “all fake” nor “always cheapest” captures the evidence.

The CMA's review page provides the wider investigation and publication context. It is worth keeping that context attached when quoting a percentage. A finding about the products, dates and retailers studied should not silently become a guarantee about every future shelf label.

There are at least four comparisons hiding in one offer

A coloured ticket can make a buying decision feel simpler than it is. It gives you a prominent comparison, but not necessarily the comparison that matters most to your budget.

These are distinct questions. An offer can perform well on the first and poorly on the others.

This does not mean you must investigate four alternatives for every onion. It means the shelf's preferred comparison should not automatically become your only one. For frequently purchased or relatively expensive items, a little familiarity with ordinary prices can make the decision much quicker.

A worked example: a real discount, a more expensive choice

Imagine a 500g product with a usual price of £4 and a loyalty price of £3. The displayed saving is £1, or 25% of the usual price.

Now imagine a suitable 400g alternative costing £2.20. The first product's loyalty price is 60p per 100g. The alternative is 55p per 100g. The offer is genuinely cheaper than its own usual price, while the alternative costs less both at the till and per unit.

Those numbers are illustrative, not current prices collected from a supermarket. Their purpose is to expose the comparison hidden by the discount percentage.

The alternative is only meaningful if it suits you. Dietary requirements, taste, convenience and how a product works in a recipe can make two apparently similar items imperfect substitutes. A lower price for something you cannot use is not a useful saving.

The right comparison therefore combines arithmetic with a practical requirement. Decide what the product needs to do, then compare suitable options on a consistent basis.

Unit prices help, provided the units match

Price per kilogram, litre or item can make different pack sizes easier to compare. The calculation is straightforward: divide the price by the quantity, then express both products using the same unit.

Suppose one pack costs £3 for 750g and another costs £2.40 for 500g. The first is £4 per kilogram; the second is £4.80 per kilogram. The larger pack offers the lower unit price, but it still requires an extra 60p at checkout.

That extra spending may be sensible if you will use the contents. It may be less useful if the larger quantity creates waste or ties up money you need for another part of the shop.

Watch for comparisons between unlike measures. A price per item and a price per 100g do not answer the same question. Nor do different product formats necessarily deliver the same usable amount. Read the quantity rather than assuming two similarly sized packages contain the same thing.

For a product bought repeatedly, learning its approximate normal unit price can be more valuable than memorising a succession of promotional percentages.

The basket can matter more than the bargain

A supermarket trip is a collection of decisions. Saving on one item does not establish that the whole basket is cheaper.

Consider an illustrative basket that would normally cost you £30. You save £2 on planned purchases, then add £5 of unplanned products because they look attractive on offer. The final spend is £33. You received discounts and spent £3 more than your original plan.

That is not necessarily a mistake. You may value the extra purchases. The mistake would be describing the trip as a £2 budget saving while ignoring the additional spending.

Separate two questions when reviewing a receipt: did I pay less for the things I intended to buy, and did the offers change what I bought? Both are useful information. Only the first is captured by the discount total some receipts display.

This is related to the wider mechanics of subscription spending: an individually attractive price can become less attractive when you look at the full pattern of expenditure.

The cheapest shop is also a question about your route

A product being cheaper across town does not automatically make a special journey worthwhile. Travel costs, time and the risk of buying additional items all belong in the decision.

Imagine saving £1.50 on one product but paying £2 in additional transport costs to obtain it. The shelf comparison remains accurate, yet the trip does not save money on those assumptions.

Alternatively, the cheaper shop may already be on your route. In that case, the additional travel cost could be negligible. The same price difference can lead to different sensible decisions for different households.

A practical approach is to distinguish routine comparisons from special trips. Keep track of a few products you buy regularly and compare them at shops you can realistically use. You do not need to optimise every item across every retailer to improve the overall value of your shopping.

Convenience has value too. Naming that value honestly is more useful than pretending the lowest shelf price is the only rational consideration.

Membership is part of the offer

A loyalty price is conditional. You need to meet the scheme's requirements and apply the membership correctly at the point of purchase.

The CMA's review publications also discuss access, including obstacles associated with age restrictions and smartphone requirements. That matters because a discount available in principle may not be equally accessible to every shopper.

Before relying on a scheme, check the current terms directly with the retailer. Can you use a physical card? Is an app required for the specific offer? Does the price apply automatically, or must a coupon be activated? Is the offer available in the store format you use?

These questions do not have one universal answer across all schemes. They are a short checklist for the offer in front of you.

Keep an eye on the checkout total. If an expected discount has not appeared, resolving it before leaving is often simpler than reconstructing the transaction later. Retain the receipt when you need to query a specific purchase.

The data question deserves its own decision

A loyalty scheme can involve an account and records of purchases associated with it. What a retailer does with those records depends on its terms and privacy information. Do not assume every programme has the same arrangements.

Read the explanation for the scheme you use, especially the sections on account information, purchase history, marketing preferences and sharing. Look for what is required to operate the programme and which communications or additional uses have separate choices.

A discount can still have monetary value while you have reservations about the accompanying data practices. Those are two dimensions of the decision. You do not need to pretend that either cancels the other automatically.

The comparison with smart-TV tracking is useful here: a convenient service can contain several separate data settings. Understanding the actual mechanism produces a better decision than assuming every company either collects nothing or sells everything.

This article does not claim to have audited every supermarket's current privacy policy. For a specific scheme, the retailer's current documents are the place to establish its stated practices.

A shopping method that takes less effort than chasing offers

Begin with a list based on what you expect to use. Mark the items where you are flexible about brand or pack size. That gives you room to benefit from an offer without letting the offer define the entire shop.

For a small set of regular purchases, note the unit prices you actually pay. You can use receipts or a simple note on your phone. A personal record does not need to cover the whole supermarket to be useful.

At the shelf, check three things: the price you qualify for, the quantity and the suitable alternatives nearby. If a larger pack wins on unit price, consider whether you will finish it.

After checkout, look at the total and any unplanned additions. Over several shops, that tells you whether the scheme is reducing your spending on your normal basket or mainly encouraging different purchases.

This is a suggested budgeting method, not a claim that one supermarket or programme will always be cheapest. The benefit comes from making your own comparison consistent.

Three quick questions about loyalty prices

Are the usual prices always inflated?

The CMA's historical findings do not support treating every usual price as an invented reference. A particular offer still needs to be judged on its own evidence. A broad suspicion is not a substitute for checking the actual product and period.

Is a 30% discount better than a 10% discount?

Only if the underlying comparison is relevant. Thirty per cent off an expensive product can leave a higher final price than a smaller discount on a suitable alternative. Compare the amount you will pay and receive.

Should you join every scheme?

That depends on the shops you use, the requirements you can meet and your preferences about accounts and data. A programme you rarely use may add complexity without much value. Start with the places that are genuinely part of your routine.

The shelf label offers one story about a saving. Your basket, your route and your actual needs supply the rest.

Sources checked 20 September 2026. CMA findings refer to its 2024 review. All worked prices and baskets in this article are illustrative, not a live supermarket price survey.