Why don't credit card purchases go through immediately? I'm kind of disappointed you didn't know the answer to this, Fresh.
It takes a couple days to go through intentionally. Remember that's billions, trillions in transactions. If they can hold onto it an extra day or two, they get interest on it.
What happens is when the merchant sends through the charge to be approved it's subtracted from your credit line immediately, but the transactions are tabulated in "batches" periodically, up to a few days. That's time the creditors have possession of the money and they still get paid interest on it. Meanwhile you, the customer, is charged interest immediately.
In the past there was a class action lawsuit against the credit card industry for this by consumers. It was thrown out quickly because the customers are not injured by it and unfortunately things like that are just a part of business.
Disclosure: I am a moderator/paid staff of this site, which does have advertising relationships with some credit cards that are discussed and linked to. Regardless, anything I say is my honest opinion.
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