Will an unlocked Apple iPhone 3GS work on Solo Mobile?

You can check if your phone can be used with Solo Mobile by using their device compatibility tool.

Link: http://www.solomobile.ca/en/support/articles/is-my-mobile-phone-compatible-with-solo

That test cannot be relied on. I bought an iPhone 3GS based on that web site telling me the phone is totally compatible based on the IMSE #.....but when you go to the Bell stores, the Solo Sim cards will not work. We have spent one hour at the store and two hours on the phone with Solo giving all kinds of different reasons, but no activation of the iPhone. Solo should stand behind their web site information, and activate the iPhone on the same plan that we have now. Seems like a good letter to write to the Toronto Star's consumer advocate Ellen Roseman.

Thank you for this information Michael. I guess the best way to do this, just to make sure, is to bring your phone to a Solo Mobile store so their reps can check the compatibility of the phone personally. Also, if you know someone with Solo, maybe you can borrow their SIM for a while and insert it to your already unlocked phone to see if it'll work.