The 'up to' speeds offered by broadband providers, although unrealistic, are the fairest way of advertising connections, according to BT.
A representative of the company was talking in the wake of Ofcom's latest report, which highlighted the discrepancy between maximum connection speeds and the average speeds actually received by customers.
The recent study showed that while most broadband subscribers in the UK are paying for speeds of 'up to' 8Mb, in reality the UK enjoys a national average of 3.6Mb.
But a BT spokesman told the Daily Mail: "The challenge with broadband is that the speed received is dependent on numerous factors, including the house's distance from an exchange, the internal wiring in that house, the condition of the copper etc.
"BT believes that advertising speeds of 'up to' is the most appropriate approach as speeds can reach that level, but that there also needs to be a speed check before a sale takes place."
An indication of the low broadband speeds seen in Britain compared with many other countries was highlighted by the 33 per cent of those questioned by Ofcom that were dissatisfied with the experience of watching or downloading TV programmes through their broadband connections.