Another trick: some banks count the purchase _authorization_ against your funds, rather than the _capture_, when you buy online. But the merchant may reject you

Another trick: some banks count the purchase _authorization_ against your funds, rather than the _capture_, when you buy online. But the merchant may reject your order if the address verification failed. If you mistype your address multiple times, you've got multiple holds on your money. Even if the merchant voids the authorization, they conveniently don't process the voids immediately. So you can end up with overdraft fees despite having enough money in your account!