Generally, I don’t believe in combining money before the legal marriage, so I would recommend waiting for the paperwork before you do combine things.
I haven’t actually done this yet, but my planning for once we’re married is that we’ll get a new joint checking account and joint saving account at his Credit Union. Then we’ll both switch our direct deposits to the new account for new money coming in. We’ll switch over payments as we can, after a couple paychecks come in.
We will transfer any extra money from our old accounts and close them a while later – when we’re sure all checks have cleared and all autopays and transfers have been closed or changed over.
We’ll get new credit cards under joint accounts, and close the old ones (we don’t carry balances but do use cards for most purchasing).
I was toying with the idea of keeping separate checking accounts to use for individual “fun money” and maybe each depositing 10% of our incomes or some set amounts into them, but Fiance isn’t too keen, so I think we won’t do that. I think we’ll maybe set up a limit to how much money we can spend on any given purchase without clearing it with the other. Maybe $100 for regular things, and $250 or $500 for special things (Christmas gifts, anniversary, etc).
We each have investment accounts and I have no idea about combining those. Our retirement accounts will stay individual, of course, but we also have outside investments. Mine are mostly at a large online brokerage, and his are in a couple individual mutual funds. Maybe we’ll just leave those as they are and get a joint brokerage account for new money to invest? I don’t know. This is one area I need to do a lot more research on!
Our state is a marital property state, so even if we did keep some stuff (investment accounts) separate, it wouldn’t necessarily stay separate legally. You might see if the state you are in is a marital property state, and just be aware if you do want to keep anything separate that you have to take particular steps (not mingle money, etc).
We don’t have any debts other than our mortgages, so luckily we don’t have to worry too much about debt, but I would say if you’re marrying someone you’re marrying their debt and it should be paid out of joint funds. You might each try to pay down debt as much as possible before marrying, just to see what you can get cleared up. I always advocate getting rid of debt!!!