Four out of five UK homes are now able to take advantage of BT's 20Mb advanced copper broadband services, it has been claimed.
BT Wholesale has confirmed that 80 per cent of households and business premises can now be connected to its ADSL2+ network, after more telephone exchanges received an upgrade.
The firm is aiming to extend coverage of its Wholesale Broadband Connect (WBC) platform to 90 per cent of the UK within 12 months.
This upgrade, set to be completed by spring 2013, is being carried out alongside BT's deployment of fibre optic cables around the UK.
The broadband provider is investing up to £2.5 billion equipping local telephone exchanges with fibre capability, allowing end users to receive download speeds of up to 100Mb.
In its February update, BT Wholesale said 80 per cent of UK homes and businesses are now enabled for WBC advanced copper services, offering an up to 20Mb broadband service "with many additional benefits".
The firm noted that all forward-looking plans are "subject to change", but described the service expectations as "reasonable".
"Because our rollout involves risks and uncertainties, actual results may differ materially from those expressed or implied by these forward-looking plans," BT Wholesale added.
The firm originally promised to deliver 20Mb broadband for 80 per cent of the UK back in April 2011.
Speaking at the time, BT Wholesale's Managing Director of Products Cameron Rejali said the announcement was "further evidence of BT's commitment to deliver next-generation services across the UK".
"Running over BT's 21st Century Network, WBC offers communications providers the ability to provide their broadband customers with greater control, choice and flexibility as well as higher speeds," he added.
"It supports the growing demand for high-speed broadband access to a range of online services – including TV, gaming online and multiple VoIP services."