T-Mobile UK was a mobile network operator in the UK, owned by Deutsche Telekom since 1999 and was originally launched as Mercury One2One in 1993. It merged with France Télécom's Orange UK to form a joint venture, EE in 2010. EE continued to operate the T-Mobile brand until February 2015, when new connections and upgrades on T-Mobile tariffs were withdrawn. Existing T-Mobile customers who wish to upgrade must switch to an EE tariff when their contract term ends, or can choose to remain on their existing T-Mobile tariff without renewing.