Can I take my soon-to-be ex-spouse's name off our joint checking account?

Your bank was probably right. The only way you can take a joint account holder's name off the account without permission is if your original contract with the bank specifically allows this—but most contracts don't and yours probably doesn't. The underlying reason is obvious—you wouldn't have wanted your husband to march into the bank a day before you and take your name off the account.

You might, however, be able to do an end run around this system. Go back to the bank and politely ask to close the joint account. Then transfer the money to another account in your name only. One catch is that your husband might still claim rights to the money during the divorce proceedings. Be prepared to show that it was really yours and yours alone. Also, some banks will only close an account that has a zero balance.