Area Code 10 – Bangkok/Nonthaburi/Pathum Thani/Samut Prakan

Geographic Allocation and Coverage

The country calling code +66 is assigned to Thailand under the ITU-T E.164 international numbering plan. Within this national plan, the prefix '10' serves as a geographic area code for the Bangkok Metropolitan Region, encompassing the capital city of Bangkok and the adjacent provinces of Nonthaburi, Pathum Thani, and Samut Prakan. This area is the political, economic, and cultural heart of Thailand, hosting the seat of government, major financial districts, and the primary international gateway, Suvarnabhumi Airport (located in Samut Prakan). The code is administered by the National Broadcasting and Telecommunications Commission (NBTC) of Thailand.

Dialing Formats and Number Structure

When dialing a fixed-line number in this region from within Thailand, subscribers use the trunk prefix '0' followed by the area code '10' and the subscriber number. The complete national significant number (NSN) is 10 digits long, including the leading '0'. For example, a local number might appear as 0 10 234 5678. From abroad, callers must omit the trunk prefix '0' and dial the country code, area code, and subscriber number: +66 10 234 5678. It is important to note that the area code '10' is part of the NSN and must always be dialed, even for local calls within the same area, due to the closed numbering plan adopted in Thailand.

Overlay and Numbering Considerations

The Bangkok Metropolitan Region is served by multiple geographic area codes, including '2' for older fixed-line services and '10' for newer allocations. This overlay approach allows for an increased supply of numbers without changing existing subscriber numbers. Consequently, local calls within the region may require dialing the full 10-digit NSN (including the area code) even for calls to the same district. For international callers, the process remains consistent: dial the international access code (e.g., 011 from the US, 00 from most European countries), followed by 66, then the area code '10' (without the leading '0'), and the 7-digit subscriber number.

Practical Guidance for Callers

• Calling from abroad: Replace the leading '0' of the Thai number with +66. For instance, a Bangkok number 0 10 345 6789 becomes +66 10 345 6789.
• Calling from a mobile phone in Thailand: Always include the '0' and the area code, even for local calls. Example: 0 10 345 6789.
• Calling from a fixed line in Thailand: Use the same 10-digit NSN format. If you encounter issues, check with your service provider regarding any required prefix for inter-operator calls.

This geographic code is exclusively for fixed-line PSTN services; mobile numbers in Thailand begin with different prefixes (e.g., 6, 8, 9) and are non-geographic. Always verify the number before dialing, as misdialing may route your call to a different province or service.