Provinces of Laos
Updates: 
The majority of sources agree that the capital of Xiangkhoang is Phônsavan, not Xiangkhoang.
Erratum: "Administrative Subdivisions of Countries" says that Luang Prabang is the capital of Laos. It should be
Vientiane. I don't know where the error originated. Merriam Webster's Geographical Dictionary, Third Edition, says that the
"administrative seat moved from Louangphrabang to Vientiane c. 1563 due to hostilities with Burmese and Thais". The Statesman's Year-Book
(1959 edition) said that Luang Prabang was currently the royal capital, and Vientiane, the administrative capital.
ISO 3166-2 Newsletter Number I-2 was published on 2002-05-21. It shows the newly created Xaisômboun special region, but calls it a
province. The error was corrected in ISO 3166-2 Newsletter number I-4, dated 2002-12-10.
FIPS PUB 10-4 is a U.S. government standard listing administrative divisions of countries and their codes. Change Notice 1, dated
December 1, 1998, lists a division of Laos into 16 provinces, one city, and one special zone. Note that the special zone is not listed in
the international standard ISO 3166-2.
The following table shows the complete set of divisions of Laos, according to the new version of FIPS PUB 10-4.
Country overview: 
| Short name | LAOS |
| ISO code | LA |
| FIPS code | LA |
| Language | Lao (lo), French (fr) |
| Time zone | +7 |
| Capital | Vientiane |
Laos was a French colony at the start of the 20th century. It was a union of two former kingdoms, Luang Prabang and Vientiane. The
French administered it as a territory within the protectorate of French Indo-China. After World War II, French Indo-China was divided up
into three independent countries within the French Union: Cambodia, Laos (independent on 1949-07-19), and Vietnam. See Cambodia for
related information.
Other names of country: 
- Danish: Laos
- Dutch: Laos, Lao Democratische Volksrepubliek (formal)
- English: Lao People's Democratic Republic (formal), Lanxang (obsolete)
- Finnish: Laos
- French: Laos m, République f démocratique populaire Lao
- German: Laos, Demokratische Volksrepublik f Laos n
- Italian: Laos m
- Lao: Saathiaranarath Prachhathipatay Prachhachhon Lao (formal)
- Norwegian: Den demokratiske folkerepublikk Laos (formal) (Bokmål), Den demokratiske folkerepublikken Laos (formal) (Nynorsk), Laos
- Portuguese: Laos m, República f Popular Democrática Lao (formal)
- Spanish: Laos, República f Democrática Popular Lao (formal)
- Swedish: Laos
Origin of name: 
ethnic name Lao, applied by Portuguese explorers in the plural
Primary subdivisions: 
Laos is divided into sixteen khoueng (provinces), one kampeng nakhon (municipality or prefecture), and one khetphiset (special region
or zone).
| Province | HASC | FIPS | Pc | Population | Area(km.²) | Area(mi.²) | Capital |
| Attapu | LA.AT | LA01 | 18 | 87,700 | 10,320 | 3,985 | Attapu (Muang Samakhisai) |
| Bokeo | LA.BK | LA22 | 05 | 114,900 | 6,196 | 2,392 | Ban Houayxay |
| Bolikhamxai | LA.BL | LA23 | 11 | 164,900 | 14,863 | 5,739 | Muang Pakxan |
| Champasak | LA.CH | LA02 | 16 | 503,300 | 15,415 | 5,952 | Pakxé |
| Houaphan | LA.HO | LA03 | 07 | 247,300 | 16,500 | 6,371 | Sam Neua |
| Khammouan | LA.KH | LA15 | 12 | 275,400 | 16,315 | 6,299 | Thakhek (Muang Khammouan) |
| Louang Namtha | LA.LM | LA16 | 03 | 115,200 | 9,325 | 3,600 | Louang Namtha |
| Louangphrabang | LA.LP | LA17 | 06 | 367,200 | 16,875 | 6,515 | Louangphrabang |
| Oudômxai | LA.OU | LA07 | 04 | 211,300 | 15,370 | 5,934 | Muang Xay |
| Phôngsali | LA.PH | LA18 | 02 | 153,400 | 16,270 | 6,282 | Phôngsali |
| Saravan | LA.SL | LA19 | 14 | 258,300 | 10,691 | 4,128 | Saravan |
| Savannakhét | LA.SV | LA20 | 13 | 674,900 | 21,774 | 8,407 | Savannakhét (Muang Khanthabouly) |
| Vientiane | LA.VI | LA27 | 10 | 286,800 | 15,927 | 6,149 | Muang Phôn-Hông |
| Vientiane [prefecture] | LA.VT | LA24 | 01 | 531,800 | 3,920 | 1,514 | Vientiane |
| Xaignabouri | LA.XA | LA13 | 08 | 293,300 | 16,389 | 6,328 | Muang Xayabury |
| Xaisômboun | LA.XS | LA25 | | | 7,105 | 2,743 | Ban Mouang Cha |
| Xékong | LA.XE | LA26 | 17 | 64,200 | 7,665 | 2,959 | Ban Phone (Muang Laman) |
| Xiangkhoang | LA.XI | LA14 | 09 | 201,200 | 15,880 | 6,131 | Phônsavan |
| 18 divisions | 4,551,100 | 236,800 | 91,429 | |
- Province: Vientiane [prefecture] is a municipality and Xaisômboun is a special region.
- HASC: Hierarchical administrative subdivision codes. If periods are replaced by
hyphens,
these are the same as the province codes from ISO standard 3166-2, except for the special zone, whose ISO code is
LA-XN.
- FIPS: Code from FIPS PUB 10-4.
- Pc: First two digits of postal codes.
- Population: 1996 estimates, based on 1995 census. Source: The Statesman's Year-Book.
- Area: Provided by Karem Abdalla.
|
Postal codes: 
Laos uses four-digit postal codes. There is not much information about them, nor many examples of usage, on the Internet. This
U.S. Postal Service
page has the best list I could find (at the
bottom of the page). Using it, I reconstructed the Pc column in the table above. The system was probably implemented before
Xaisômboun special region was created.
Further subdivisions:
See the Districts of Laos page.
The provinces are further subdivided into muong (districts).
Origins of names: 
Vientiane: Lao vieng: city, chan: sandalwood
Change history: 
- 1904: Two Siamese (Thai) provinces, corresponding to modern Xaignabouri and parts of Louangphrabang and Vientiane, annexed to Laos.
Stoeng Trêng province transferred from Laos to Cambodge.
- 1941: The same provinces were restored to Thailand under pressure from Japan.
- 1947: The same provinces reverted to Laos as pre-war boundaries were restored.
- 1966: Name of Nam Tha province changed to Houakhong.
- ~1969: Capital of Xiangkhoang moved from Xiangkhoang to Phônsavan after the former was destroyed by bombing.
- ~1972: Name of capital of Khammouan province changed from Thakhek to Muang Khammouan.
- 1973-11-20: Champhon province (capital Ban Kengkok) temporarily split from Savannakhét; Vangviang province (Muang Vangviang)
temporarily created from parts of Louangphrabang and Vientiane.
- 1973-12-26: Hôngxa province (Muang Hôngxa) and Paklay (Muang Paklay) temporarily split from Xaignabouri.
- ~1976: (Capitals in parentheses.) Name of Houakhong province changed back to Louang Namtha; Borikhan province (Muang Pakxan) merged
with Vientiane; Xédôn (Pakxé) and Sithandon (Muang Khong) provinces merged with Champasak (Champasak); Vapikhamthong
province (Muang Khôngxédôn) merged with Saravan; Oudômxai province split from Louangphrabang.
- 1983: Bokeo province split from Louang Namtha (formerly FIPS=LA05); Bolikhamxai province formed from parts of Khammouan (LA04) and
Vientiane (LA11) provinces; Xékong province split from Saravan (LA09).
- ~1987: Capital of Oudômxai province moved from Ban Nahin to Muang Xay.
- ~1989: Vientiane prefecture split from Vientiane province (LA21); capital of Vientiane province moved from Vientiane to Muang
Phôn-Hông.
- 1994-06: Xaisômboun khetphiset (special region) formed from parts of Bolikhamxai, Vientiane, and Xiangkhoang provinces.
Other names of subdivisions: 
In transcription from Lao, some sources break names at syllable endings (e.g. Boli Kham Xai)
- Attapu: Atpu, Attapeu, Attopeu, Muang Mai (variant)
- Bolikhamxai: Bolikhamsai, Bolikhamxay, Borikhamzay (variant); Borikane, Borikhan, Borikhane (obsolete)
- Champasak: Bassac, Champassack, Champassak (variant); Champassac, Khong, Pakse (French)
- Houaphan: Hua Phan, Huaphanh (variant); Sam Neua, Xam Nua (obsolete)
- Khammouan: Khammouane, Khammuan, Khammuane (variant)
- Louang Namtha: Haut-Mekong (French-obsolete); Luangnamtha, Muong Luang Namtha, Namtha (variant); Hiuakhong, Houa Khong, Upper Mekong (obsolete)
- Louangphrabang: Loang Prabang, Louangphabang, Louang Prabang, Luang Phabang, Luangphrabang, Luang Prabang (variant)
- Oudômxai: Oudomsai, Oudomsay, Oudomxay, UdomXay (variant)
- Phôngsali: Fong Sali, Phongsaly (variant)
- Saravan: Salavan, Salavane, Saravane (variant)
- Savannakhét: Svannakhet (variant)
- Vientiane: Viangchan (variant)
- Vientiane [prefecture]: Kamphaeng Nakhon Viang Chan (formal)
- Xaignabouri: Sayaboury, Xaignabouli, Xayabouri, Xayabury (variant)
- Xaisômboun: Saysomboune, Xaysomboun (variant)
- Xékong: Sekhong, Sekong (variant)
- Xiangkhoang: Xiang Khouang, Xieng Khouang, Xiengkhuang, Xieng Khwang (variant)