If the call diversion feature is added to your account, follow the below steps to activate it.
1: Dial *21*
2: Dial the number you want it to divert to
3: submit the number by pressing #
4: To Deactivate Call Diversion dial #21#
If an announcement is readout stating the feature is unavailable, please contact customer services contact us at firstname.lastname@example.org or 0333 202 5000 option 1 for Customer Services then option 2 for Landline and Broadband and a member of the team will be happy to assist as the feature may be faulty or is not live against your phone line.