MMI errors, also known as Man-Machine Interface errors, occur when the following happens:
- The phone doesn't understand what you are trying to do.
- What you are trying to do is invalid (e.g. inputting the wrong activation codes).
- The phone is not subscribed to the service you are trying to perform (in this case, conditional call forwarding).
Prepaid carriers get the MMI error because setting up conditional call forwarding is not possible or an allowed feature for them. When conditional call forwarding should be working but it is not, it’s because the sim card doesn't understand that you are subscribed or allowed to perform that action.
Please take a look at our interactive help guide below to resolve your MMI issues!