Peter, Roman is correct. The SpeakOut brochure that used to be on 7-11's website says, "5¢ per text message sent or received to Canadian Wireless Numbers. 10¢ per text message sent to US Wireless Numbers. 25¢ per text message to International Wireless Numbers." It doesn't explicitly say that all SMS incoming is 5¢, however, Petro-Can Mobility's FAQ does.

To confuse matters some more, I just sent an SMS message to my SO phone using my United Mobile SIM which has a UK phone number. (IOW I sent an international SMS originating in Canada to a UK phone number for delivery to a Canadian phone number.) The text arrived almost instantaneously (I used the UM SIM with a different phone) but so far my SO airtime balance remains unchanged.

Now here's a possible explanation. UM's roaming partner in Canada is Rogers. Is it possible that Rogers detected that the call originated in Canada for delivery in Canada and therefore routed everything within Canada? Even so, I should have been charged 5¢ for receiving a domestic SMS, shouldn't I?

P.S. UM updates their airtime debits overnight so I won't know until tomorrow if and how much they charged me.