Is Black Friday actually cheaper in the UK?
The honest answer is: some of it, and not the parts you would expect.
Some of it is real. Much of it is not
Black Friday produces genuine reductions in a few categories and theatre in most of the rest. The reliable ones are where shops genuinely want stock gone: superseded televisions, last-generation laptops and phones, and large appliances.
The unreliable ones are products created for the event. A model that exists only in November, at a specification slightly below the year-round range, is not discounted — it is a cheaper product priced to look like a discount.
The reference price is the trick
A discount is a claim about two numbers, and only one of them is visible. UK pricing rules require that a "was" price was genuinely charged for a meaningful period, but the interpretation is generous and a brief spell at a high price can legitimise a long spell at a lower one.
So the percentage tells you nothing. What tells you something is whether the current price is lower than the price at other shops today, and whether it is lower than this product usually costs.
What to do instead of waiting
- Decide what you want in advance, by specification, and write down the model number. Deciding during the sale is how the sale wins.
- Check the price across shops on the day. A genuine Black Friday price will still be a genuine price when compared against four other retailers.
- Ignore the percentage entirely. It is a claim about a number you cannot see.
- Be most suspicious of the best deals in the categories that never normally discount.
When the sale genuinely is the best time
Large appliances, televisions from the outgoing range, and superseded laptops tend to be honestly cheaper during the event, because the retailer has a real commercial reason to clear them. If you already wanted one of those, the sale is a reasonable time to buy.
For everything else, the question is not "is this a Black Friday deal". It is "is this cheaper than the same thing elsewhere, right now".