Method and device for reminding telephone number change

The present invention provides a method and a device for reminding telephone number change, wherein, a switch receives a calling request from a calling subscriber to a called subscriber, while the calling request comprises an original number of the called subscriber. According to the original number, a first piece of inquiry information is transmitted to a subscriber database for inquiring whether the called subscriber changes the original number. The subscriber database inquiries a service which is subscribed by the called subscriber according to the inquiry request information from the switch, generates and transmits a first piece of inquiry response information to the switch. The switch determines whether the called subscriber changes the original number to a new number according to the first piece of inquiry response information. When the called subscriber has changed to the new number, the switch transmits a piece of reminding information to a short message service center, wherein the indicating informat