To call a telephone number in Greece from the UK: Dial the international call prefix. For calls from the UK this is 00 (or ‘+’ from mobile phones). Dial the country code for Greece – 30.
Do I need to dial 011 from UK?
Follow these steps to call the UK from the US: Dial the exit code 011. This will let your carrier know you’re making an international call. … If you’re calling a UK cell phone, dial 7 after the area code.