If I am given credentials to a bank account willingly by someone, but am not officially a person on the account, am I not allowed legally to use the account?
I ask that, since it appears there was no hacking involved here, so I assume this is an account she had access to from when they were together.
In the legal sense, authorization to access the account is not mediated by knowledge of the necessary credentials, it is mediated by permission from the account owner.
If you are given them while married and then continue to use them after a divorce, no I don't think so.
Imagine it was the keys to her personal apartment she had in her name during marriage. It would not be ok for her husband to enter there after they were divorced.
Change gender of the Accused. A woman and man go through a divorce, the man continue to keep tab of his ex-wife through their previous shared bank account. Does that sound like a crime, even if there was no hacking involved?
Are you asking me what I think of it on an ethical level? I was more curious about the actual legalities of it or not.
Because if it is actually a crime, me and my partner have been committing that crime on some of our accounts.
Personally, I don't find it to be criminal no. Like giving keys to my appartment to a friend when I'm away on vacation to check on my dog. Obviously, if they come in my house and steal things that's different, but if they were to come in for some seemingly reasonable reason and I didn't want them doing that anymore I should ask for the key back or change my lock.
A divorce can be a pretty nasty thing for all parties involved. Had you shared your bank account with your significant other in an informal way, such as giving them your user/password for it, but not actually made them an official account holder, and during the divorce if the partner signs in for something seemingly reasonable, like making sure there's enough money to pay the bills, I also don't find that criminal. You probably need to have a talk about this, and might want to change your password if you don't want this happening anymore. Again, would be very different if money was transferred out and stolen.
I don't know what the correct answer is, but I've known people who gave their ATM card to a relative so the relative could get cash. I think this used to be more common but is potentially risking legal trouble these days.
Of course, I'm old enough to remember when cereal box offers would say "Tape four quarters to a piece of cardboard and mail that in with your request as payment for this offer."
The breach of contract in theory means the bank is not liable for any ensuing damages, and that you are. But in the case of the OP it may not be especially pertinent.
I ask that, since it appears there was no hacking involved here, so I assume this is an account she had access to from when they were together.