Area Code 37 – Nakhon Nayok/Prachin Buri/Sa Kaeo
The phone area code for Nakhon Nayok/Prachin Buri/Sa Kaeo is 37 (international format +6637). Browse local exchange codes (NXX) and carrier assignments below.
📍 Geographic Location of Nakhon Nayok/Prachin Buri/Sa Kaeo
Geographic Coverage and Administrative Scope
The Thai national destination code (NDC) +66 37 is a geographic area code assigned to the eastern Thai provinces of Nakhon Nayok, Prachin Buri, and Sa Kaeo. These provinces form part of Thailand's eastern economic corridor, with Prachin Buri serving as a major industrial hub. The code covers both provincial capitals and rural districts, including the Khao Yai National Park region in Nakhon Nayok and the border trade area of Aranyaprathet in Sa Kaeo.
Dialing Formats and Number Structure
Within Thailand, calls to these provinces require the trunk prefix 0 followed by the area code and the subscriber number. The complete national significant number (NSN) is 9 digits long, comprising the area code (2 digits) and a 7-digit local subscriber number. For example, a landline in Prachin Buri might be dialed as 0 37 123 456 nationally. Internationally, callers must use the country code +66 and drop the leading trunk prefix, resulting in +66 37 123 456. This format applies to both PSTN and VoIP services.
Caller Instructions
- Local callers within the same province can often dial only the 7-digit subscriber number, depending on the operator's local dialing plan. However, for calls from other provinces, the full national format 0 37 XXX XXXX is required.
- International callers should replace the trunk prefix '0' with the Thai country code '+66', so the number becomes +66 37 XXX XXXX. Ensure you include the plus sign when using a mobile phone or the appropriate international access code (e.g., 00) from a landline.
Overlay and Numbering Considerations
Thailand has not implemented overlay codes for this geographic area; the 037 code remains exclusive to these provinces. However, number portability allows subscribers to retain their numbers when switching between fixed-line operators. It is important to note that while the code is geographic, some businesses may use VoIP services to obtain a virtual number with this area code, allowing them to establish a local presence without a physical office in the region.
Practical Usage and Examples
For a business in Nakhon Nayok, the international dialing format would be +66 37 234 567. If you are calling from Bangkok, you would dial 0 37 234 567. Always verify the subscriber number length, as some older lines may have fewer digits, but the standard is 7 digits after the area code.