I've always felt the same, but a few situations have required separate accounts: - education savings accounts for children. There's some tax advantage to keepi

I've always felt the same, but a few situations have required separate accounts: - education savings accounts for children. There's some tax advantage to keeping them separate. - a checking account for a personal assistant to pay bills from, limited to a few months cash - when living together with separate finances, a household account that you both contribute to with a debit card. Convenient for splitting groceries, home improvement, etc. Otherwise, you have to keep receipts and settle regularly. - if you're paying tax to 2 countries with a tax treaty, you may have to prove that you've already been taxed on money you're bringing in. It's best if you can do that from an account with only a single source of income, or else it gets complicated.