[nbm]

In general, the two biggest financial benefits have to do with reduced health (and other) insurance rates, and not paying taxes on all or some of gifts, inheritance, or other wealth transfers between spouses (similar to those between parents and children).

The largest financial penalty in many countries is that spouses will pay more income-related taxes in dual-income families vs. if they were single, due to how progressive taxation bands are set up.

The benefits of government recognition for most people who marry aren’t financial - they’re to do with parental, health, estate, citizenship/immigration-related, and other rights that largely can’t fully be reliably created by contracts.

[alisonkisk]

In the US, marriage is tax neutral or decrease except for when two $200K+/yr earners are married.