BT is offering its customers the chance to boost their broadband speed for free with the launch of faster headline speeds of up to 20Mb/s and the BT Broadband Accelerator.

BT Retail broadband customers already has download speeds of up to 8Mb/s, and in enabled areas that will leap to up to 20Mb/s. Upload speeds will also increase from up to 448Kb/s to up to 1Mb, the company said.

According to BT, the speeds of up to 20Mb/s will initially be available through 549 exchanges serving 10 million or 40% of the UK’s homes and businesses. It expects the coverage to increase to 55% by March 2010.

The company is also offering the BT Broadband Accelerator, a speed booster pack for free to its broadband customers who order it online, although they will have to pay £1.2 for postage. The Broadband Accelerator includes a small plate that allows customers to insert it into their main telephone socket to reduce the impact of electrical interference. This is expected to increase broadband speed by 1.5Mb.

The Broadband Accelerator plate, also known as the I-Plate, isolates a redundant wire in the socket which can slow connections. Even if it does not improve speed, the device can help stabilise broadband lines making them even more reliable, the company claims.

John Petter, managing director of BT’s consumer division, said: “The BT Broadband Accelerator can make a big difference to the speed of your broadband. We think it is so important we’ve taken the decision to offer it to our customers for just the cost of the postage.

“Between that and us more than doubling headline speeds for millions of homes and businesses, most customers should start to see a rapid boost in the performance of their connection. We have a track record of not charging customers any more when we increase the speed and this time is no different. BT broadband customers won’t have to pay any more to get higher speeds.”