Area Code 16 – Bangkok/Nonthaburi/Pathum Thani/Samut Prakan

Geographic Coverage and Administrative Jurisdiction

The +66 16 prefix is a geographic area code assigned to the Bangkok Metropolitan Region, encompassing the capital city of Bangkok and the adjacent provinces of Nonthaburi, Pathum Thani, and Samut Prakan. This allocation falls under the National Numbering Plan administered by the National Broadcasting and Telecommunications Commission (NBTC) of Thailand. The area code serves as a National Destination Code (NDC) for fixed-line telephone services within this densely populated economic zone, which hosts the country's primary government institutions, financial districts, and industrial estates.

Dialing Formats and Number Structure

When dialing a number with the 16 prefix from within Thailand, callers must use the trunk prefix '0' followed by the area code and the subscriber number. The complete national format is 0 16 XXX XXXX, where '0' is the trunk prefix, '16' is the area code, and the remaining seven digits constitute the local subscriber number. For international callers, the country code +66 replaces the leading '0', resulting in the format +66 16 XXX XXXX. For example, a local call to a Bangkok number would be dialed as 0 16 234 5678, while an international caller would dial +66 16 234 5678.

Overlays and Numbering Considerations

The 16 prefix is part of a broader numbering plan that includes multiple area codes serving the same metropolitan region, such as 2 (Bangkok) and 3 (Nonthaburi, Pathum Thani, Samut Prakan). This overlay structure allows for an increased supply of telephone numbers without requiring changes to existing numbers. Subscribers within the coverage area may have numbers from different area codes, and calls between these codes are typically charged at local or reduced rates. It is essential for callers to always include the area code when dialing from outside the immediate local calling area, even when calling a number within the same province.

Caller Instructions

For local callers within Thailand: Always dial the trunk prefix '0' before the area code, even for calls within the same province. For example, to call a number in Bangkok from another province, dial 0 16 XXX XXXX. For international callers: Dial your country's international access code (e.g., 011 from the US, 00 from most European countries), followed by Thailand's country code 66, then the area code without the leading '0', and the subscriber number. For instance, from the US, you would dial 011 66 16 XXX XXXX. Ensure you omit the '0' trunk prefix when dialing from abroad.

This geographic code is vital for businesses and residents in the Bangkok metropolitan area, facilitating reliable PSTN connectivity. As Thailand continues to expand its telecommunications infrastructure, the 16 prefix remains a stable identifier for fixed-line services in this key economic region.