My wife and I used to have one account, and I would micromanage her spending and it caused a lot of resentment between both of us. It's easy to assume that one partner just wants to lord over other, but that wasn't the case. I hated it. My wife was a little care-free with her spending, and it caused me to be fearful for our finances.

She wasn't selfish or necessarily irresponsible. She was typically spending money on the family or gifts for friends. Still, every time money got tight, I would go through the bank statement so I could understand what happened. I would start asking questions about her spending and it made her defensive and it made me apprehensive. There are times I would stop looking at the bank account, but ignoring the problem would only make things worse.

Finally, we created two new accounts, one for her and one for me. We agreed we would pay our living expenses and shared stuff (like family excursions and stuff for our kids) out of the joint account. All expenditures from the joint account had to be agreed to (that way we were both to blame for any shortfall). The two individual accounts were for discretionary spending. We both got the same allowance and we were allowed to spend that money anyway we wanted to.

Truth is, I never liked monitoring her spending. Once she had her own account, I didn't have to. If she ran out of money between paychecks, that was her problem. She enjoyed the freedom to spend money the way she wanted. I think she really like not being blamed for any financial issues we have. I personally liked not blaming her anymore. The three account system has made things so much easier for us.