How to solve the problem that the caller ID number of mobile phone is unknown?

Use third-party applications, contact operators, etc.

1. Use third-party applications: If you often receive calls or text messages with unknown numbers, you can use some third-party applications to solve this problem. These applications can help identify the source of unknown numbers and block incoming calls or text messages from spammers or telephone harassers.

2. Contact the operator: If the phone screen keeps displaying unknown numbers, you can contact the operator for help. Operators may help solve this problem or provide solutions.