What is the reason why mobile phones can't make calls and receive short messages abroad?

1. If you have started roaming in Hong Kong, Macao and Taiwan and internationally, but you can't use this function when roaming abroad, there may be the following reasons:

1. Some countries or regions have different network standards and frequency bands, so it is necessary to replace appropriate mobile terminals to use the international roaming function;

2. The mobile phone is set to automatically select the network, and no operator can be found to cooperate with our company. You can manually select a network by changing the setting to "Select Network Manually".

2. When you encounter problems in international roaming and need help, please call China Unicom's international roaming customer service telephone number+8618618610010. We will provide you with 7×24 hours free service. Making overseas calls through Unicom's mobile phone is free, and domestic calls will be charged normally.

If you have any questions, please click /qALCW for consultation.