I answer 'Hello?' to all personal calls, or possibly a slightly warmer 'hey?' to friends.
(I'm of the generation that never phones, only messages, so there's always an element of surprise when someone phones, hence the question mark. You might be my best friend, yes, but why are you ringing me?)
In the office (UK) I answer the phone with the office name. 99% of the time, the conversation runs as follows:
Bring bring! Bring bring!
Me: Company Name
Other person: Hello, can I speak to (boss's name) please?
Me: Sorry, he's not here. Can I help at all?
Other person: I'm ringing from (company name) about XYZ.
Me: Can I take your name and telephone number, please?
Other person: (Name and tel no.) Thanks for your help. What was your name, please?
Me: first name.
Other person: thanks for your help (first name)! Goodbye.
It's completely standard. It's entirely possible that neither person will give their name until the dying breath of the phone call. And it's possible you'll only exchange first names, unless you're spelling out an email address or passing their details on to someone else.
It would never have occurred to me that other cultures might think it rude not to introduce yourself first.