How do I know if a phone is unlocked?

Related questions

1. What happens when a phone is blacklisted?
2. Can someone use a stolen iPhone?
3. Is my phone network locked?
4. How do I know which carrier My phone is locked to?
5. Is a blacklisted iPhone useless?
6. Is my phone locked to Telstra?
7. Can you still use a blacklisted phone?
8. How do I check my battery serial number?
9. Is my phone blacklisted?
10. How do I know if my battery is original?

Tags

1. #unlock
2. #telling
3. #purchased
4. #enter
5. #probably
6. #another
7. #greeted
8. #originally
9. #service
10. #phone
11. #locked
12. #check
13. #dialog
14. #carrier
15. #making
16. #unlocked
17. #valid