There's no instructions on this. Some people's cards last more than 10 years. Some people only have a few months. When you find that the mobile phone card often shows the insertion of the SIM card, the card should be replaced with wear and tear, and the understanding of poor contact that the mobile phone number can not be used, if there is obvious poor contact, the signal is unstable, it needs to be replaced, generally three years
Mobile phone sim card how often to change this is according to your own needs, you think this mobile phone number can not be used, then you can immediately replace, if your mobile phone number is very good, you can always do not change is OK. So sm card want to change, no matter how long you can change.
The mobile phone card can be changed once every three years or so. Change once every three years, not only for safety, but also to prevent the aging of the mobile phone card chip, resulting in poor contact, unstable signal reception and other situations.