unlocking with T-Mobile
T-Mobile charge a flat fee of £15.32 for unlocking phones. For Pay-As-You-Go customers the service is available after 3 months. For Contract customers it is available after one month.
The phone number to request a "network subsidy code" is 0845 412 5000 .
T-Mobile states that it will be sent by post up to 28 days later though by some accounts it doesn't usually take that long.