If you're in a long-term relationship and you trust your significant other, a joint bank account can be an excellent tool to help you manage your money effectively and achieve financial goals together. First, you won't have to pay the fees twice. Second, drawing up a budget and sticking to it might be easier when you both pool your money together. Also, if one of you has to be away for an extended time frame, the other person can take care of all the financial aspects.
The key to a successful joint bank account is trust. It's important that both account holders establish clear ground rules and that the lines of communication are not only open but used often. If you have even the smallest doubt about your partner, then don't open a joint bank account and give them full access to your money. You could create a joint account where you deposit a limited amount of funds, while keeping your primary salary account separate and in your name only.