Broadband speed claims: what the “average speed” figure really means

When you compare broadband, the biggest number is rarely the one you experience. UK advertising rules say a numerical speed claim in a broadband advert must be the average download speed that at least 50% of that provider’s customers receive at the network’s busiest time, 8pm to 10pm, and it must be described as an average. Those rules are set by the Advertising Standards Authority and are policed through the CAP and BCAP codes. Separately, the broadband industry’s voluntary codes of practice, published by Ofcom, expect providers to give customers a speed estimate at the point of sale, and to work peak-time congestion into the “normally available” and “minimum guaranteed” speeds they quote. What that means in practice is that three figures matter, not one: 1. The advertised average speed, which is the 8pm to 10pm figure at least half of customers get. 2. The minimum guaranteed speed, the floor the provider commits to and the one that gives you a right to exit if it is consistently missed. 3. The estimated speed for your own address, which depends on your line, your exchange and how many neighbours share it. A cheaper deal with a lower average can be a better buy than a premium package if your line cannot feed the faster one. Ask the provider for your address estimate before you sign, note the minimum guarantee in your order confirmation, and check the mid-contract price rise before you compare monthly cost. If an advert quotes a speed that is not described as an average, or quotes a maximum as though it were typical, that is an advertising matter for the ASA rather than a comparison question.