How can I switch my primary and secondary lines when I move between countries?

Hi fcardenas,

Thanks for coming to Apple Support Communities for help today.

This article can show you how to set up a default number, label your line and even set which contacts use which line when you call: Using Dual SIM with an eSIM.

If you just want to switch your number, when you cross the border and want to make a call, see this section:

"Switch phone numbers for a call

You can switch phone numbers before you make a call. If you're calling someone in your Favorites list, follow these steps:

1. Tap the Info button .
2. Tap the current phone number. 
3. Tap your other number.

If you're using the keypad, follow these steps:

1. Enter the phone number.
2. Tap the phone number, near the top of the screen. 
3. Tap the number you want to use."

Have a fantastic day!