There are two ways to end up in a better seat: bid cash for it, or use eUpgrade credits you have earned. People lose money confusing them.
After you book an eligible cash fare, Air Canada may invite you to bid cash for a higher cabin. You get a sliding scale with a minimum and a maximum, you enter an amount and a card, and you wait. If the bid is accepted you are charged, usually around the check-in window or a few days before departure.
It is a gamble, not a purchase. Most bids are decided shortly before the flight, and a bid sitting inside the "recommended" range can still be declined if higher bids or paying customers fill the cabin. Until it clears, plan to fly the seat you booked.
No. The minimum is fixed the moment you bid, and it does not fall as the flight nears. Watching it in hope of a lower number is wasted effort.
Your only other path to a cheaper upgrade is asking at the airport, where an agent quotes whatever cash price is left on the day. That number is independent of your online bid: sometimes lower, often not, never guaranteed.
If only one premium seat is available, a bid for two passengers can clear for one of you. You end up upgraded alone while your companion stays in the original cabin.
Some upgrade offers let you bid points instead of cash. Avoid it. Points spent on a bid redeem at roughly one cent each, which is well below what you should get from a flight award.
If you would aim for one and a half to two cents per point on a redemption, spending those same points on an upgrade bid is one of the weakest uses available. Pay the bid in cash if you bid at all, and keep your points for a flight. For how to judge a redemption's value, see business class points vs cash.
Three routes to a better seat, each for a different situation.
No. It is set when you bid and does not fall as the flight fills. The only other option is a cash price quoted at the airport, which is unrelated to your bid.
Yes. If one premium seat is open, a bid for two can upgrade one passenger only. A single seat can sometimes be declined at the boarding desk if you would rather stay together.
Cash. Points on a bid redeem at about one cent each, far below a good flight redemption. Save the points and pay the bid in cash if you bid at all.
Use an eUpgrade when you have credits and qualifying status. Bid cash when you do not. When the cabins are close in price, buying the higher fare outright can beat both.
Come in for a free conversation. We can look at your fare, status, and credits together and tell you whether a bid, an eUpgrade, or a different fare is the better move.