You should have your Telus phone unlocked first before you can have it activated with the Virgin Mobile network.
Telus might give you information on how to unlock your phone, so you might want to try asking them. There may be a fee associated with doing this. Alternately, the phone's manufacturer might be able to give you some information about unlocking it.
Even if the phone is unlocked, it might not work on Virgin Mobile network. You have to email them your phone's IMEI number, and they will look it up in their systems to see if it's compatible.
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