Acer Liquid Z630 User Manual page 61

Selecting which SIM to use when making a call
If you have set Calls to Always ask, you will be asked which SIM to
use each time you make call. Enter the number, then tap
opens; tap the SIM to use and the call will be connected.
Selecting which SIM to use when sending a text message
If you have set SMS Messages to Always ask, you will be asked
which SIM to use each time you send a text message. Enter the
message and recipient information, then tap the Send button. A dialog
opens; tap the SIM to use and the message will be sent.
Managing your SIM cards - 61
. A dialog