"Pre-auth" works the same way for VISA/MC debit and VISA/MC credit. The amount is (temporarily) deducted from my available balance when I use a debit card, jus

"Pre-auth" works the same way for VISA/MC debit and VISA/MC credit. The amount is (temporarily) deducted from my available balance when I use a debit card, just like it is deducted from the credit limit when I use a credit card.