To activate call forwarding on a landline phone, sign up to include call forwarding in the phone plan, dial an activation code and input the phone number for forwarding. If there is no answer from the forwarded number, repeat the input process.
Most standard phone service plans do not include call forwarding, so call the service provider to sign up for it. Pick up the receiver, and dial the two-digit code based on the preferred forwarding method. The code 72 is used for unconditional call forwarding, and 68 sets up call forwarding that activates if the line is busy or the receiver does not pick up. Code 63 allows forwarding only to specific numbers. Some services allow users to forward calls only when the line is busy using the code 90, and 92 forwards the call only if no one picks up. These codes apply to most landline phones in the United States.
After inputting the code, dial the 10-digit phone number to be used for forwarding. The feature is activated when the call is answered. If this doesn't work, hang up and try again. Activation methods may vary for phones with Sprint Nextel and all cell phones that do not use a 1G network.