If you send a text message to a teacher, can the teacher go to the business office to check the name of the student with that phone number? Is it illegal?

There is no such regulation. Are you too naughty? You should repent if you make a mistake. What's going on? Tell the truth and communicate well.

Believe that teachers always want the best for their students~

There are always reasons for things. You can’t determine what the specific situation is from what you say, so you have to do it yourself. Understand~

Communication between people

is very important. It’s better to understand each other. If there is any misunderstanding, it is best to resolve it as soon as possible, otherwise you will feel uneasy.