Seems OFCOM are being daft again, see http://www.bbc.co.uk/news/technology-33083056
One of the issues with the code of practice, which, last time I looked, was voluntary, was that it defines all lines at or lower than the 10th percentile of similar services as being "faulty" and so could be ceased for no charge.
This causes a load of issues.
For as start, the "no charge" is simple for any ISP to work around. Make the router you supply free as long as you take service for X months, then if you cease within that for any reason you have to pay for the router. Supply of a router is not a communications service, it is a simple sale of goods, and so not covered by the OFCOM rules or ADR. You could even invoice it on 6 months terms with an agreement of a bonus/credit once you have the service for 6 months meaning you won't have to pay the invoice. So OFCOM trying to change business models of ISPs where the install and equipment is cheap in return for a minimum term simply won't work.
However, the far bigger issue is simply defining 1 in 10 lines as faulty. It is mental. It does not encourage an ISP to do anything about slow lines, as whatever they do they will always have 1 in 10 lines defines as faulty.
Indeed, it actually encourages ISPs to try and have 10% of lines working really slowly if the customer is not actually complaining, perhaps even deliberately so, as that lowers the 10th percentile speed and removes the issue of people leaving because of slow speeds. After all, if the ISP fixes those slow lines, or the ISP loses those slow line customers, they just have a higher 10th percentile and more lines that are impossible to improve as they are working as well as the service can let them.
I agree, making estimates at point of sale as accurate as possible, and even the idea that failing to meet those is reason to leave, is sensible. But if you are on a long line and have an estimate of 1Mb/s and get 1Mb/s why should you be able to consider that a fault just because you are in the lowest 10%? You canna change the laws of physics captain - there will always be 10% of the people on the longest lines and they will not be "fixable" just because they are on long lines!
Of course for more modern links, like FTTP, you get even more crazy. OFCOM defined it as lines at or lower than 10th percentile. When all lines get exactly 80Mb/s on a fibre to the premises, that means all of them are at or lower than the 10th percentile! The better the ISPs service the worse the problem for them and so OFCOM are discouraging good service and speed.
If OFCOM start insisting on this code of practice we will start a telemetry package deliberately clamped at a very slow sync rate on DSL, and sell that to people with parking meters and signage and credit card terminals and so on. That way we can try and get the 10th percentile down to like 250kb/s and be immune from this stupidity.