Thai Industrial Standard 1099-2548

Thai Industry Standard 1099-2548 (short TIS 1099) is a national standard assigning numerical codes to the administrative subdivisions of Thailand, published in 2005 by the Thai Industrial Standards Institute.

In 1992, a first version of the TIS 1099 standard (named TIS 1099-2535) was published, assigning codes to each of the then 72 provinces and the capital city of Bangkok. It followed a numbering scheme already used within the Ministry of Interior since the 1980s.

The ISO standard 3199-2, first published in 1998, follows the codes of this standard. The draft version of ISO 3166 was based on the US standard FIPS 10-4, which assigns different numbers to the provinces. Additionally to the codes for the province and Bangkok, the ISO standard adds a special code for the special administrative area Pattaya, a code not present in the Thai standard.

In 2005, the current version of the standard was published, introducing the codes for Amnat Charoen, Nong Bua Lam Phu and Sa Kaeo, created in 1993. It also introduced codes for every district and subdistrict, and some of the municipalities, especially those already existing before the sanitary districts were made into municipalities in 1999.

Since the last publication of the standard, the province Bueng Kan and the district Galyani Vadhana as well as some subdistricts in Bangkok were created. Numerical codes for these entities have been assigned by the Ministry of Interior, which continues to publish regular updates to their code list.

Every province has a 2 digit numerical code assigned, starting with 10 for Bangkok till 96 for Narathiwat Province. However, not all codes in between are used, some are kept for future use. The first digit designates a region, based on the administrative region as they were in use in the 1950s. The second digit enumerates the provinces within the region. As there are now already 12 provinces in the region 4, the northern Isan, the codes 38 and 39 have been used for the latest provinces in this region.

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