SMS authentication is widely used and recognized as an authentication method that can easily strengthen security, but it cannot solve all issues.
Low-cost SIM users may not be able to use it
Major carriers such buy telemarketing data as NTT Docomo, au, and Softbank offer SMS services as a standard feature from the start. However, users of low-cost SIM cards may not be able to use SMS depending on their plan. As SMS authentication is widespread across many services, you may need to change your plan.
②Depending on your SMS reception settings, messages may not be received.
If the recipient of the SMS has been set to reject messages, the verification code may not be received and the service may not be available. If you are unable to receive the verification code during two-step verification, please check the rejection settings.
There are other what is link farming & should you participate? reasons why SMS may not be delivered. Please refer to the following article for reasons why SMS may not be delivered and how to deal with it.
If you lose your device, cancel your contract, or change your model, you may not be able to log in. This is because you need to confirm the code sent to your mobile phone number to proceed with two-step authentication. In particular, if you cancel your mobile phone contract, there is a possibility that the “authentication code lithuania phone number” may be leaked to someone else. You need to be careful when handling your device, which functions like a physical key.
