You can only use Canada post Xpresspost prepaid envelop in order to track your application for return and it is also recommended by CIC. No matter if you enclosed let say UPS or fedex prepaid envelop but CIC will send your passport by Canada post regular mail. I would simply use Canada post Xpresspost. Some times too much sugar spoil the appetite. This is just my 2 cents choice is yours.john123ui said:guys one question: CIC has specifically mentioned <b> two (2) PREPAID Canada Post Xpresspost envelopes (National), letter-sized (318 x 241 mm), at any Canada Post retail outlet </b>. can I not use any other courier service and their envelops.. looks fine to me but a confirmation will be helpful...