[iMore Question]

Only mobile numbers can be used to send an SMS to.
I need to add a second number which will be recognised as a number that a message can be sent to, as this contact have different mobile numbers in when travelling abroad.

[kch50428]

Add the number, change its label to mobile... in the edit screen, just tap the label, and you can change it to one of the available choices.

[HankAZ]

Use either iPhone or Mobile as the label for the phone number, as Keith suggested above.

[memski88]

you should be able to from contacts and edit, it gives you the option of work cell home phone number you can add emails too