Area Code 551 – Hefei/Chaohu, Anhui
The phone area code for Hefei/Chaohu, Anhui is 551 (international format +86551). Browse local exchange codes (NXX) and carrier assignments below.
📞 Exchange Codes (NXX) for Area Code 551
Select a central office code to view local carrier data and detailed information
📍 Geographic Location of Hefei/Chaohu, Anhui
Geographic Coverage and Administrative Jurisdiction
The +86 551 area code is a geographic National Destination Code (NDC) assigned to the city of Hefei, the capital of Anhui Province in eastern China. Hefei serves as the political, economic, and cultural hub of the province, and the area code also covers the adjacent county-level city of Chaohu, which is administratively under Hefei's jurisdiction. The region is a major transportation and technology center, home to numerous universities and research institutions.
Dialing Formats and Caller Instructions
For local callers within the 551 area code region, the standard domestic dialing format is simply the 8-digit subscriber number, without any trunk prefix. For example, to call a local landline in Hefei, you would dial the 8-digit number directly.
For callers from other parts of China, the domestic long-distance format requires dialing the trunk prefix 0 followed by the area code and subscriber number: 0 551 XXXX XXXX. For instance, a call from Beijing to a Hefei landline would be dialed as 0551 XXXX XXXX.
For international callers, the format is the country code, area code (without the leading zero), and subscriber number: +86 551 XXXX XXXX. For example, a caller from the United States would dial 011 86 551 XXXX XXXX, while a caller from the United Kingdom would dial 00 86 551 XXXX XXXX.
Overlay Considerations and Numbering Plan
Currently, the 551 area code is not subject to an overlay plan, meaning that no additional area codes have been introduced for the same geographic region. Subscriber numbers within this area code are 8 digits long, and the total length of a national significant number (NSN) for a landline in Hefei is 11 digits (including the leading 0 for domestic calls). The numbering plan follows the ITU-T E.164 recommendation, ensuring global interoperability.
Important Notes for Callers
When dialing from abroad, it is crucial to omit the trunk prefix '0' that is used for domestic long-distance calls. Additionally, mobile numbers in China are not tied to geographic area codes and use separate prefixes (e.g., 13x, 15x, 18x). If you are unsure whether a number is mobile or fixed, note that fixed-line numbers in Hefei are always 8 digits after the area code, while mobile numbers are 11 digits and begin with specific mobile prefixes. For the most accurate and up-to-date dialing instructions, always consult your telecom provider or the official numbering plan resources.