BT's broadband customer base now stands at over four million, making it the first provider to pass the figure.
According to figures from BT, the firm has added one million customers in the last year to further stretch its lead as the UK's largest broadband provider.
When BT launched its new business plan in June 2002 - the kernel of which was to make broadband and IT services a priority - it had just 172,000 subscribers.
Ian Livingston, head of BT Retail told the Independent that hitting the figure of four million represents a "great achievement in such a short time".
He added: "Broadband has proved to be one of the most popular new services ever seen ... broadband can provide so many more services than just internet surfing, and it has become central to many people's lives and businesses."
BT's growth has been assisted by its acquisition of smaller rival broadband providers such as Plusnet and Brightview.
Prior to BT's emergence as the UK's largest provider earlier this year, Virgin Media had led the field.