Huawei
Set Default SIM for Calls auf Huawei
On dual-SIM Huawei phones, EMUI decides which card handles outgoing calls unless you set a fixed default. This matters for Quick dial, quick contacts, and any call shortcut that does not ask you to pick a SIM manually.
Without a default calling SIM, the system may default to whichever card had the last active connection, which can trigger roaming fees or calls placed from a line you did not intend to use.
To fix this, go to Open the settings ➔ Tap on Mobile network ➔ Tap on SIM management ➔ Tap on Default calling SIM ➔ Choose a default calling SIM. Select the SIM slot you want every outgoing call to use by default.
This setting only affects the default, not calls where you manually pick a card before dialing. Apps and shortcuts that ask for a SIM per call, like the standard dialer, still show a selection prompt when you place those calls.
If you use one SIM mainly for data and the other for voice, setting the calling default separately from the data SIM avoids confusion when tapping a contact from your call log or favorites.