Around 50 jobs are at risk at EE's North Tyneside office.
Owned by the BT Group, the firm is planning to reduce its customer service team at its office at Colbat Business Park.
In documents seen by ChronicleLive, it states there are fewer calls coming into the service contact centres due to various digital channels being available.
The company plans to start withdrawing the service in the New Year, with the full withdrawal complete by April 2020.
But the firm states it is trying to find suitable alternative roles for staff.
The move is part of a UK wide restructure that will see 77 jobs at risk in total.
A BT spokesperson said: “We are considering restructuring proposals predominantly within our enterprise service operations in North Tyneside that will impact a small number of colleagues.
"These proposals form part of our work to streamline processes and adapt to the changing ways in which customers wish to interact with BT Enterprise.
"As part of that process, we have begun consulting with potentially impacted employees and their union and employee representatives.
"We will look to re-skill and redeploy impacted colleagues wherever possible, and in some cases there may be an option to take voluntary redundancy.
"We will take these steps to try and minimise any compulsory redundancy.”
