Consumers are still facing obstacles to switching broadband provider, despite new rules designed to ease the process, research shows.

A year ago, Ofcom, the independent regulator and competition authority for the communications industry, said that broadband suppliers must give customers a migration authorisation code (MAC) -- a unique alphanumeric reference that allows phone line-based broadband users to switch provider smoothly -- upon request and free-of-charge within five days of its request.

But a poll of 1,480 people who tried to change broadband provider in the past 12 months found that some providers are failing to stick to the rules.

Some 38 percent of those questioned by YouGov for price comparison service uSwitch.com said they did not receive their MAC within five days of it being requested, and 14 percent said the code failed to materialise at all.

That is worse than before the new rules came into force: 11 percent of 3,090 broadband customers who switched over 12 months ago and needed a MAC to do so did not receive the code.

Steve Weller, head of communications at uSwitch.com, said: "Despite the mandatory code of practice being introduced, providers are still dragging their heels at the customer's expense.

"MAC codes not only enable customers to move to a new broadband service quickly and smoothly, but they ensure that bills from the old supplier stop.

"They are so vital that some companies actually refuse to sign new customers up if they don't have a code."

Broadband prices have hit a new low after dropping by a third in the past four years, research says.

Customers now pay an average £17.19 per month compared with £26.66 in December 2003, according to price comparison website uSwitch.com.

Broadband connections have also got quicker, increasing from headline speeds of an average 0.5Mb in December 2003 to 8Mb now.

Orange currently has the highest monthly charge for stand-alone broadband at £20 for speeds of up to 8Mb, uSwitch said.

AOL has brought in the biggest reduction of the past four years, cutting its monthly broadband charge from £27.99 in December 2003 to £14.99 this year.

Steve Weller, head of communications services at uSwitch.com, said: "With broadband both the cheapest and the fastest it's ever been, our love affair with the internet is set to reach great heights this year.

"We predict that prices will stabilise, but customers will be offered more for their money, with companies continuing to increase speeds."

Plusnet currently offers the cheapest monthly 8Mb deal at £10 per month, uSwitch said.

The fastest broadband connection speed in December 2003 was a 2Mb package from Telewest.

Virgin Media is now planning to roll out a super-fast 50Mb broadband service by the end of 2008.