Are Extended Warranties Ever Worth It? The Expected Value

Take a £450 washing machine with the usual one-year manufacturer warranty, and a five-year plan for a one-off £190 (mid-range for the plans above). The plan's incremental cover is years 2-5. Suppose the machine has some probability p of a breakdown in that window, an average repair costs £170, and total write-offs get a £450 replacement.

The breakeven failure probability if claims are repairs: £190 / £170 = 112%. Literally impossible - even a guaranteed single repair would not return the premium. If every claim were a full £450 replacement: £190 / £450 = 42%. The plan only breaks even if two in five machines die completely within five years.

Now plug in a generous real-world failure belief - say p = 20% in years 2-5, with claims split between repair and replacement (average benefit £250):

EV = 0.20 x £250 - £190 = -£140

You pay £190 for something worth £50 in expectation. Even doubling the failure rate to 40% leaves the cover £90 underwater. Retailers are not confused about this: warranty margins are among the best in electrical retail precisely because the premium is set several multiples above expected claims - a textbook negative expected value product from the buyer's side.

The multiplication can flip positive when three things stack: a genuinely high failure rate, expensive repairs, and a cheap, long plan. A £35 five-year plan on a £1,200 appliance with a 25% failure probability and £400 average repairs has EV = 0.25 x £400 - £35 = +£65. Deals like that exist - usually manufacturer promotions (free or token-price extended cover for registering the product) rather than till-point retail plans.

Two other cases deserve a mention. First, genuinely fragile, heavily-used, costly-to-fix items (a laptop that commutes daily) can carry failure-x-cost numbers high enough to justify some price of cover - though accidental-damage insurance and the till-point warranty are different products, and the till price is rarely the cheap way to buy it. Second, if a surprise £400 bill would be genuinely unaffordable rather than merely annoying, insurance can be rational even at negative EV - you are buying protection from ruin, not maximising expectation. A washing machine rarely qualifies.

Loss aversion makes a possible £450 loss feel roughly twice as painful as a £450 gain feels good, so we overpay to delete small, survivable risks. Warranty pricing is that bias with a barcode. The tell: nobody insures their £40 kettle through a broker, but plenty of people say yes to £3.50 a month for it at the checkout, where the pain of imagining the loss is freshest. The rational frame is self-insurance. Put the £7 a month you would have spent on cover into a repairs pot instead. Across all your appliances and gadgets, some will break and most will not - and because you are diversified across many items, your pot almost certainly ends ahead of the premiums. You keep the float; the retailer was keeping it before. Insurance belongs on risks that could ruin you (house, liability, income), not on anything you could rebuy with a grimace.

UK law quietly covers a large slice of what extended warranties sell back to you:

• Consumer Rights Act 2015: goods must be of satisfactory quality and reasonably durable. If a fault is inherent (present at purchase, even if it surfaces later), the retailer is liable - you can pursue a repair, replacement or partial refund for up to 6 years in England and Wales (5 years from discovery in Scotland). After the first 6 months you may need to show the fault was inherent, but for a premature appliance failure that is often straightforward.
• Section 75 of the Consumer Credit Act: pay £100-£30,000 by credit card and the card issuer is jointly liable with the retailer for faulty goods - useful leverage if the retailer stalls or goes bust.
• Manufacturer goodwill and registration offers: many appliance brands offer free extended parts warranties (sometimes 5-10 years) just for registering the product - genuinely free EV, claimed in five minutes.

An extended warranty's incremental value is only what it pays beyond all of the above - mostly wear-and-tear failures that are not inherent faults, plus convenience (no arguing, one phone line). Convenience is worth something. It is rarely worth 3-5x the expected claims.

Sources

• Which?: Worthless warranties - are you overpaying for faulty goods cover?
• Currys: Care & Repair plans
• gov.uk: Consumer protection rights
• Citizens Advice: getting your money back if you paid by card

Worked figures are our own calculations from the premiums and assumptions stated in the text; they illustrate the arithmetic and are not financial advice.