I'm a bit confused about how NSF fees on a signature-based debit card can occur; when an authorization is made, there's a hold on the amount - that amount can't be accessed by the account holder; then when the settlement claim comes in, how can there be insufficient funds and an NSF charge?
Thanks, Anjali

Although the amount may be on hold and can't be accessed electronically the account holder can still write a check of the funds. Say I have $100 in my account and make a purchase for $90 on Monday morning. Before that purchase clears my account I can still go to the Bank (or any check casher for that matter) and write a check for $90 because at the Bank it looks like I still have the $100. Then when the purchase clears my account after settlement there's really only $10 left in the account to cover it.

Is that right? That leaves me even more puzzled - what's the the point of a hold, if the funds can be accessed (whether by check or atm or anyway else? Also, what is the protection to the merchant, or does the account holder honor the settlement claim and recover from the account holder?
I read somewhere today that the reason NSFs occur on an offline debit card, is because banks place the authorization hold for a short period (1-5 days), and if the settlement claim comes in after the hold 'falls', then there can be an NSF charge. Can anyone confirm, please?
But still, the query re the merchant's claim holds..
Thanks,
Anjali