Openreach has criticised broadband providers for not doing enough to let people know about network upgrades.
BT's infrastructure division has said it has made superfast broadband available to more than 26 million premises across the country.
However, it is concerned because only around a quarter of them have actually upgraded.
Openreach believes this is partly because many companies that use its network are not letting customers know about enhancements that have been made.
This, it said, means many consumers are complaining about poor broadband connectivity without knowing they could switch to a superfast fibre connection.
As a result, Openreach is looking to take control of the situation by launching an advertising campaign, which explicitly tells people that a faster fibre service is not an automatic process and that they must sign up to receive speedier connections.
Posters and leaflets pushing this message are being displayed and distributed in Aberdeen, Cambridge, Carlisle, Coventry, Derby, Edinburgh, Exeter and Ipswich - cities where Openreach believes the take-up of superfast broadband has been particularly low.
The organisation added that if the campaign yields strong results, it could be extended to more parts of the country.
This unusual move comes as the debate over Openreach's future relationship with BT continues to rumble on.
Ofcom has ordered BT to give more independence and investment powers to Openreach, with the broadband subsidiary being run as a distinct and legally separate company with its own board.
The watchdog believes its proposals will provide Openreach with the greatest possible degree of independence without separating the companies entirely, and lead to decisions being taken for the good of its customers and the wider telecoms industry.
Sky, TalkTalk and Vodafone have all been vocal in backing a full structural separation of BT and Openreach.