SMS prompts 400 megabytes of traffic.

Every morning, you will receive a reminder message of traffic speed limit, which may be caused by the following reasons:

1.** Traffic reminder function has been enabled * *. Both China Mobile and China Unicom can open the traffic reminder function, and some operators also provide daily, weekly and monthly reminders.

2.* * The traffic really exceeds * *. This is the most common reason. When the traffic usage exceeds the package threshold, operators will send SMS reminders to users, and make different speed limit treatments according to the excess.

As for the traffic used by children at night, this may also be one of the reasons, but it is more likely that parents have opened a family number or a family package, and the child's mobile phone number and the parents' mobile phone number are in the same package. When children's mobile phones use traffic, parents' mobile phones will also receive SMS reminders.

The above information is for reference only. You can call the operator's customer service hotline or go to the local business hall for details.