How to switch the primary number and secondary number in iphone SMS?

1, open the information program of iPhone 1 1, and click the letter icon to create new information;

2. Enter the mobile phone number of the recipient, or click the "+"sign behind the recipient to select the recipient from the address book;

3. If the recipient number is not in the address book, clicking Edit SMS will pop up the current default SIM card; If the recipient number is in the address book, the current default SIM card will pop up directly after selecting the recipient.

4. Click the current default SIM card, and the minor number and major number will pop up at the bottom of the screen for selection;

5. If you select the secondary number at this time, you will switch to the secondary number to send short messages.