T-Mobile UK [SEP] parent company
EE tariff when their contract term ends, or can choose to remain on their existing T-Mobile tariff without renewing.
History.
The network was originally launched as "Mercury One2One", a GSM mobile network operated by the now-defunct Mercury Communications. It was the world's first GSM 1800 network when it was launched in September 1993. It was later rebranded as simply "One2One", when it was operated for a short time as a joint venture between Cable & Wireless plc and American cable provider Mediaone
the merger of their UK based operations, causing Orange UK and T-Mobile UK to cease to exist as companies, although they continued as brands.
On 11 May 2010 it was announced that both the Orange and T-Mobile brands would remain on British high streets, although their new merged parent company will be called EE.
In September 2012, T-Mobile's parent company EE announced that all Orange and T-Mobile stores were to be re-branded as 'EE' stores by 30 October 2012