Ofcom has outlined how it will ensure a reformed Openreach is meeting its obligations.
Earlier this year, BT agreed to Ofcom's demand for Openreach to become a distinct and legally separate company.
The regulator had sought changes to Openreach's governance as it was concerned BT still had control over its decisions, while other telecoms firms were not adequately consulted on investment plans that would affect them.
Openreach will therefore be separated from BT and will operate with its own staff, management, strategy and a legal purpose to serve all of its customers equally.
Ofcom has now offered details on how Openreach will be held to account to "ensure it delivers for phone and broadband users".
The regulator will closely scrutinise how effectively Openreach serves the whole industry, as well as measure how far it is improving its network and helping to deliver a better quality of service.
Ofcom will also monitor whether all UK consumers and businesses using Openreach’s network are receiving "decent speeds and the right service to meet their needs".
In addition, Openreach's contribution to growing fibre broadband networks will be scrutinised, while it will be expected to be responsive to different investment models put forward by its customers.
If Ofcom deems that Openreach's new operating structure is not working, or that BT is failing to honour its commitments, it would be prepared to "revisit the model and consider new measures to address any concerns".
Sharon White, Chief Executive of Ofcom, said: "The new Openreach will be built to serve all its customers equally, acting independently and taking investment decisions on behalf of all its customers.
"BT has made positive progress towards implementing the reforms. Once they are complete, Ofcom will keep a careful eye on whether Openreach is working for telecoms users, ensuring BT and Openreach live by the letter and spirit of their commitments."
Ms White added that the regulator will not "hesitate to act" if it sees any problems emerging.