NO sim card lasts forever unless you use it at least once in a specific period of time. The terms & conditions vary from 1 carrier to another, however in general for pre-paid cards, in order to keep your card active, you need to at least top up the card (minimum top up amount allowed by the carrier is fine but it's usually no less than 5 $/€/£), make a call or send a message (any of these 3 chargeable actions) once per 180 days (6 months) with some carriers extending it to as much as 270 days. So, no carrier requires that you top up every month. Some special pre-paid cards can last for 1 year tops, however they are non-reusable anymore after 1 year (they are one-time use only), most of the times they are for data/internet use only (however you CAN receive verification messages from FB/IG etc... to verify your accounts) and most importantly cost too damn much (like $30-50 per card) which make them useless for verifying accounts.
All of the above holds true for European countries only as I have done a lot of research on this topic, because I own more than 500+ sim cards to verify my FB accounts and I live in Europe. For US/CA/AU though, I have no idea. If I were you, I would research if you can use European sim cards in Canada and if you can, buy them for cheap on Ebay. Local shops and Ebay have been my 2 sources for a long time with Ebay being my primary source only very recently.
However, please keep in mind that you will need to change cards and re-verify accounts every 6 months though, unfortunately there is no way around it. I started using UK cards recently and I am slowly replacing all my old local shop cards (thank god because I was going to 3 different shops every 6 months to buy tons of cards at once) and the minimum top up amount imposed by the UK carriers is too much (£5) to renew the cards every 6 months, when a card costs as little as £0.5 in bulk on Ebay.
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