To unlock a 2nd-hand phone you need to call Customer Services on 0800 956 6000 (option 2, option 4) to put you in touch with the Unlocking Team to request an Unlock Code. You will be asked for your email addy. They will take payment (of £8.99) from any valid UK bank card.
Once the process has been started you will receive an email from the Unlocking Team to process the unlock. It can take up to 10 days to complete the unlock.
But even so beware that EE could still refuse to unlock it. Many phones sold 2nd-hand have been reported lost or stolen, have been sold by the original owner when under 6 months old without EE's permission or have money owing on them.
If that is the case your only remedy is against whoever you got the phone from.
__________________________________________________________________________________________ If you think I helped please feel free to hit the "Star" button below. To phone EE: The local rate landline number 020 7362 0200 or Freephone 0800 079 8586 - Option 1 for Mobiles; Option 2 for 4G WiFi; Option 3 for Home Broadband & EE TV.
ISPs: 1999: Freeserve 48K Dial-Up => 2005: Wanadoo 1 Meg BB => 2007: Orange 2 Meg BB => 2008: Orange 8 Meg LLU => 2010: Orange 16 Meg LLU => 2011: Orange 20 Meg WBC