The Motorola Razr BR50 is a thin flip phone. The Motorola company provides each Razr model with the option to block calls, so users do not have to go through their service provider to do so. Blocking calls on the Razr BR50 requires the same process as blocking calls on any other Motorola mobile phone.
Select "Settings" and "Security" from the phone's main menu.
Enter the lock code, which is the last four digits of your cellphone number. This will give you access to the security settings.
Select "Limit Use" and then "Restrict Incoming Calls." You have the option of blocking "All," or "Except Contacts." Scroll down to "Except Contacts" and click it. Select "Save" and then click the "Back" button to return to the main menu. The phone will now block all calls except those saved to your contact list.