Why doesn't Apple's SMS display its name?

If you use a domestic card, for example, the number is 13xxxxx, then if you call anywhere abroad, it is still 13xxxxx in China, but the other party cannot know whether you are roaming.

If you use a foreign card or a Hong Kong card, the natural number will change. The other party will display the number of your newly purchased card, and the number will be preceded by the local area code.

It is strongly recommended that you buy a local card outside the mainland (as long as it is supported by your mobile phone), otherwise you will incur high roaming charges, SMS charges and traffic charges.

If the other party dials your number13xxxxx, then the other party's mobile phone can't show whether you are roaming or not, and it can't show the extra charge.