The area code for the southern region of Orange County, including Irvine, is 949.

The 949 area code was established in 1998 when it was split from the 714 area code, and it serves southern Orange County and some inland areas. Cities such as Irvine, Newport Beach, Laguna Beach, San Clemente, Costa Mesa, Lake Forest, Mission Viejo, Aliso Viejo, and Laguna Niguel all use the 949 area code.

The phone number format is represented in the standard U.S. format as (949) XXX-XXXX. When making an international call from Korea to Irvine, you dial the U.S. country code +1 in front, resulting in the format +1 (949) XXX-XXXX. Conversely, when calling from Irvine to Korea, you prepend the Korean country code +82 and drop the leading 0 from the area code. For example, to call a Seoul number 02-1234-5678, you would dial +82-2-1234-5678.

When opening a mobile phone number in Irvine, you are generally assigned a number with the 949 area code; however, since it is a mobile number, calls can be made from any area regardless of the actual number's location. Major U.S. mobile carriers include AT&T, Verizon, and T-Mobile, while MVNO services like Metro by T-Mobile, Cricket, Mint Mobile, and Boost are also popular. Within the Irvine Korean community, there are instances of using Korean telecom agent offices that provide Korean language support.

Here are the contact numbers for key institutions in Irvine: Irvine City Hall: (949) 724-6000. Irvine Police Department (emergency 911): non-emergency reporting (949) 724-7000. Irvine Fire Department: (949) 724-7500. Irvine Unified School District (IUSD): (949) 936-5000. Irvine Public Library: (949) 454-5560. UCI (UC Irvine) main: (949) 824-5011. Orange County Social Services: (714) 541-7700. Orange County Health Department: (714) 834-3500.

Internet services are available throughout Irvine from providers like Spectrum (cable), AT&T Fiber (fiber optic), and Cox Communications. Some new developments may have exclusive contracts with specific ISPs, so it's advisable to check the internet service provider for the address before moving. The city of Irvine also operates free public Wi-Fi in some public spaces. Many Korean households utilize VoIP services (e.g., Google Voice, Vonage) for affordable domestic and international calls to Korea.