Tor: Can I log into my usual accounts through Tor?

Short answer

Yes, but the service will know which account you used, so that activity is no longer anonymous to that service. Tor can still hide your home IP address from it. Some banks and email providers may challenge or lock a login from an unfamiliar Tor exit location. Use HTTPS and avoid mixing an anonymous persona with personally identified accounts in the same session.

Sources

Tor Project: Managing identities, Tor Project: Secure connections.