[toast0]

I didn't see anybody mention this, but one important thing is if you are / will be living in a community property state.

If you live in a community property state, and you want to keep things legally separate, that takes a lot of specific effort. I've always lived in community property states, my spouse and I took relatively zero assets into the marriage, and we're on the same page with spending and frugality, so I was 100% on board with joint accounts and delegated authority on the primary checking account. Keeping one checking account for two people is a labor savings. We ended up with separately managed credit cards, so if we make a big purchase on the other's card, we communicate. And I manage the primary checking account, but she has custody of the checkbook; so if she one of her credit cards has a large payment or writes a big check, we communicate. If there's any big changes in our investments, we communicate.

If you're living close to your means, communication will be necessarily more frequent. If you're living well below your means, you don't need to talk frequently about money because a payment that needs pre-authorization isn't as big.

For cars, it would probably be most flexible to have ownership as X or Y, but all of our cars are under my name at the moment because it was less effort. The house is in both of our names.

[2rsf]

In many places it is not even possible to register a car on two names, although legally this is more about having a point of contact and less about ownership