When you have a joint account, both parties have equal access to the funds. If you aren't on the best terms with the co-owner of your account, it is in your best interest to remove the name. Even if you and your former mate remain close friends after a split, it is always wise to cut financial ties to release your financial liability.
Contact your bank to determine its policy on removing a name from a joint account. Each bank has its own policy and requirements. For example, Wells Fargo does not allow customers to remove one name from a joint account, even if both parties agree. The only way a name can be removed is by closing the existing account and opening a new account in your name only.
Go to the bank in person with the other account holder. You can never remove a name from a joint account without the other person's consent. If your bank does allow you to remove the other person from your account, you will need to complete the process in person. Both parties will need to show identification. If the other account holder is deceased, provide the bank a copy of the death certificate.
Complete a "Relinquishment of Rights" form allowing the other party to sign off on the account. The bank account must have a positive balance.
As joint bank account owners, you have equal rights and access to the money in the account. Either party can withdraw cash or write a check drafting the funds. Once the funds are out, close the account. As long as the account is open, you are both equally responsible for any overdraft or returned check fees.
Open a new account. After closing the account, use the funds to open a new account solely in your name.