BT's highly-anticipated return to the consumer mobile market is said to have run into technical difficulties, which could push back the launch until the second quarter of 2015.
The telco giant is reportedly planning to draw on its 5.4 million Wi-Fi hotspots to carry the bulk of its network's voice and data traffic to keep costs down for its customers.
Whenever there is a shortfall in Wi-Fi connectivity for its customers, EE's 4G network will be used to connect calls and offer internet services for users, at a cost to BT.
This is the result of an MVNO deal struck between the pair, details of which emerged earlier this year.
However, company sources have told The Daily Telegraph the firm is having problems with the technology that will make this arrangement possible.
In particular, the report states BT has encountered issues when trying to provide users with a seamless connectivity experience between Wi-Fi hotspots and EE's network, resulting in interrupted calls.
"The handover is absolutely essential for BT to do what it wants to do with mobile," the source told The Telegraph.
"It's possible the launch will slip into the second quarter of next year now."
Previously, BT had said it hopes to launch its consumer mobile services by April 2015, but its apparent technology issues could put paid to this.
In a statement to IT Pro, a BT spokesperson said: "We have always been very clear that it will take the best part of two years to develop our Consumer femtocell service and this remains the case."
