Sorin Cosoveanu and Frédéric Zanetta called my attention to five newly formed prefectures. They are described under Change history. There is some confusion over whether Anié is a prefecture or a sub-prefecture; I concluded the former.

Prefecture	HASC	Population	Capital
Agou	TG.PL.AG	84,890	Agou-Gadzepé
Akébou	TG.PL.AK	62,245	Kougnohou
Amou	TG.PL.AM	105,091	Amlamé
Anié	TG.PL.AN	95,090	Anié
Assoli	TG.KA.AS	51,491	Bafilo
Avé	TG.MA.AV	97,830	Kévé
Bas-Mono	TG.MA.BM	88,846	Afagnangan
Bassar	TG.KA.BA	119,717	Bassar
Binah	TG.KA.BI	70,054	Pagouda
Blitta	TG.CE.BL	137,658	Blitta
Cinkassé	TG.SA.CI	78,592	Cinkassé
Dankpen	TG.KA.DP	130,723	Guérin-Kouka
Danyi	TG.PL.DY	38,742	Danyi-Apéyémé
Doufelgou	TG.KA.DO	78,635	Niamtougou
Est-Mono	TG.PL.ES	121,789	Elavagnon
Golfe	TG.MA.GF	1,570,283	Lomé
Haho	TG.PL.HA	247,817	Notsé
Kéran	TG.KA.KE	94,061	Kandé
Kloto	TG.PL.KT	139,043	Kpalimé
Kozah	TG.KA.KO	225,259	Kara
Kpélé	TG.PL.KP	75,890	Kpélé-Adéta
Kpendjal	TG.SA.KP	155,091	Mandouri
Lacs	TG.MA.LC	172,148	Aného
Moyen-Mono	TG.PL.MO	77,286	Tohoun
Ogou	TG.PL.OU	226,308	Atakpamé
Oti	TG.SA.OT	190,543	Mango
Sotouboua	TG.CE.SO	158,425	Sotouboua
Tandjouaré	TG.SA.TA	117,519	Tandjouaré
Tchamba	TG.CE.TB	131,674	Tchamba
Tchaoudjo	TG.CE.TD	190,114	Sokodé
Tône	TG.SA.TN	286,479	Dapaong
Vo	TG.MA.VO	210,075	Vogan
Wawa	TG.PL.WW	100,974	Badou
Yoto	TG.MA.YO	165,596	Tabligbo
Zio	TG.MA.ZI	295,177	Tsévié
35 divisions		6,653,945
HASC: Hierarchical administrative subdivision codes. Middle two letters represent the region. For key, see Regions of Togo page. Population: 2010 census.

Change history:

1. 1960-04-27: Togo became independent. Before that time, the secondary subdivisions were ten cercles (circles). The circles were replaced by 17 circonscriptions administratives (administrative circumscriptions), further subdivided into 158 cantons. The circumscriptions were Akposso (Hihéatro), Aného, Atakpamé, Bafilo, Bassari, Dapango, Kandé, Klouto (Palimé), Lama-Kara, Lomé, Niamtougou, Nuatja, Pagouda, Sansanné-Mango, Sokodé, Tabligbo, Tsévié. The capitals had the same names as the circumscriptions except as indicated in parentheses.
2. 1968-01-26: Sotouboua circumscription created from parts of Atakpamé and Sokodé.
3. 1969-02-22: Vogan circumscription split from Aného.
4. ~1970: Name of Sansanné-Mango circumscription, but not its capital, changed to Mango. This is the set of circumscriptions at that time. (Source: Encyclopædia Britannica, 1984 edition.)

Circumscription	Reg	Population	Area(km.²)
Akposso	PL	132,000	4,382
Aného	MA	121,000	712
Atakpamé	PL	106,000	6,145
Bafilo	CE	29,000	938
Bassari	CE	95,000	6,330
Dapango	SA	181,000	4,840
Kandé	KA	42,000	1,692
Klouto	PL	77,000	2,790
Lama-Kara	KA	96,000	1,085
Lomé	MA	231,000	345
Mango	SA	58,000	3,762
Niamtougou	KA	52,000	1,120
Nuatja	PL	157,000	3,658
Pagouda	KA	45,000	465
Sokodé	CE	106,000	5,692
Sotouboua	CE	68,000	7,490
Tabligbo	MA	72,000	1,250
Tsévié	MA	156,000	3,338
Vogan	MA	132,000	750
19 circumscriptions		1,956,000	56,784
Reg: Region in which the prefecture lies. For key, see Regions of Togo page. Population: 1970-04-30 census.

1. Note: Bafilo and Bassari circumscriptions are pretty clearly in Kara region according to current maps. Either the EB was mistaken, or the boundary between Kara and Centre region changed.
2. 1974-05-08: Akposso circumscription split into Amlamé and Badou.
3. 1975-02-03: Tchamba circumscription split from Sokodé.
4. ~1982: Name of Dapango circumscription changed to Dapaong.
5. 1981-06-23: Laws No. 81-8 and 81-9 took effect. Status of circumscriptions changed to prefectures. These laws may also have been responsible for creating Kara region. Here are a map  and another map  showing the prefectures as of the period roughly from 1981 to 1995.

Prefecture	ISO	FIPS	Reg	Alternate
Amlamé	AM	TO01	PL	Amou
Aného	AN	TO02	MA	Anécho, Lacs
Atakpamé	AT	TO03	PL	Ogou
Badou	BD	TO15	PL	Wawa
Bafilo	BF	TO04	CE	Assoli
Bassar	BS	TO05	CE	Bassari
Dapaong	DA	TO06	SA	Dapango, Tôné
Kanté	KA	TO07	KA	Kandé, Kéran
Klouto	KL	TO08	PL	Kloto, Kpalimé, Palimé
Kpagouda	KP	TO14	KA	Binah, Pagouda
Lama-Kara	LK	TO09	KA	Kara, Kozah
Lomé	LO	TO10	MA	Golfe
Mango	MA	TO11	SA	Oti, Sansanne-Mango
Niamtougou	NI	TO12	KA	Doufelgou
Notsé	NI	TO13	PL	Haho, Nuatja
Sotouboua	SO	TO16	CE
Tabligbo	TA	TO17	MA	Yoto
Tchamba	TB	TO19	CE	Nyala
Tchaoudjo	TO	TO20	CE	Sokodé
Tsévié	TS	TO18	MA	Zio
Vogan	VO	TO21	MA	Vo
ISO: Codes from ISO/DIS 3166-2. (Duplicated code NI is an error in the draft standard.) FIPS: Codes from FIPS PUB 10-4. Reg: Region in which the prefecture lies. For key, see Regions of Togo page. Capital: Capitals have the same names as their prefectures, as shown in the first column. Alternate: Alternate and variant names for the prefecture. Note: Klouto and Palimé are both cities in Klouto prefecture. The alternate names may be due to a change of capital.

1. The CIA World Factbook (1990-98 editions) said that Togo was divided into circumscriptions, noting that their status may have been changed to prefectures. It gave a list which was approximately the same as the one above. It said that name changes had been reported for the prefectures, replacing the prefecture name with one of its alternate names. In 1992 and later editions, some errors crept in. Pagouda appeared twice in the list, and Nyala and Tchamba were listed as two separate prefectures, instead of alternate names for one. There were now apparently 23 prefecture names, but the text said there were 21, which was correct. In 1994, someone apparently noticed the disparity. Instead of fixing the list of prefectures, they changed the number from 21 to 23. In the 1997 issue, the number was changed back to 21, and the alternate names were dropped; also, a couple of the names were changed. In the 1999 edition, the five regions were listed, with no further subdivisions.
2. ~1995: Prefectures reorganized. Many of them changed their names to the alternate name. Dankpen prefecture split from Bassar; Moyen-Mono prefecture split from Haho; Agou and Danyi prefectures split from Kloto; Est-Mono prefecture split from Ogou; Blitta prefecture split from Sotouboua; Kpendjal prefecture split from Tône; Tandjouaré prefecture formed from parts of Oti and Tône; part of Tône prefecture transferred to Oti; and Avé prefecture split from Zio. Lomé commune may have been part of Golfe prefecture in fact, but its population and area are split out in the census data, so I list it separately. The result was as shown in this table, from sources [5] and [6], among others. The total of the areas of all the prefectures in one region (source [6]) is only roughly equal to the area of the region.

Prefecture	HASC	Population	Area(km.²)	Capital
Agou	TG.PL.AG	86,000	1,026	Agou-Gadzépé
Amou	TG.PL.AM	106,000	2,003	Amlamé
Assoli	TG.KA.AS	52,000	938	Bafilo
Avé	TG.MA.AV	93,000	1,146	Kévé
Bassar	TG.KA.BA	106,000	3,620	Bassar
Binah	TG.KA.BI	66,000	480	Pagouda
Blitta	TG.CE.BL	109,000	2,973	Blitta
Dankpen	TG.KA.DP	75,000	2,690	Guérin-Kouka
Danyi	TG.PL.DY	44,000	387	Danyi-Apéyémé
Doufelgou	TG.KA.DO	84,000	1,275	Niamtougou
Est-Mono	TG.PL.ES	81,000	2,474	Elavagnon
Golfe	TG.MA.GO	414,000	190	Lomé
Haho	TG.PL.HA	196,000	3,034	Notsé
Kéran	TG.KA.KE	72,000	1,660	Kandé
Kloto	TG.PL.KL	196,000	1,364	Kpalimé
Kozah	TG.KA.KO	214,000	1,075	Kara
Kpendjal	TG.SA.KP	117,000	1,794	Mandouri
Lacs	TG.MA.LA	229,000	706	Aného
Lomé	TG.MA.LO	963,000	90	Lomé
Moyen-Mono	TG.PL.MO	78,000	607	Tohoun
Ogou	TG.PL.OG	271,000	3,609	Atakpamé
Oti	TG.SA.OT	135,000	4,313	Mango
Sotouboua	TG.CE.SO	136,000	4,487	Sotouboua
Tandjouaré	TG.SA.TA	90,000	848	Tandjouaré
Tchamba	TG.CE.TB	81,000	3,149	Tchamba
Tchaoudjo	TG.CE.TD	168,000	2,708	Sokodé
Tône	TG.SA.TO	268,000	1,515	Dapaong
Vo	TG.MA.VO	220,000	714	Vogan
Wawa	TG.PL.WA	164,000	2,471	Badou
Yoto	TG.MA.YO	161,000	1,200	Tabligbo
Zio	TG.MA.ZI	262,000	2,054	Tsévié
31 divisions		5,337,000	56,600
Prefecture: except Lomé, which is a commune. HASC: Hierarchical administrative subdivision codes. Middle two letters represent the region. For key, see Regions of Togo page. Population: 2006 estimate.

1. 2009-11-26: Akébou, Bas-Mono, Cinkassé, and Kpélé prefectures created by elevating the corresponding sub-prefectures to prefecture status. Anié prefecture created by taking Adogbénou, Anié, Atchinèdji, Glitto, and Pallakoko cantons from Ogou prefecture. Akébou prefecture was probably split from Wawa; Bas-Mono definitely from Lacs; Cinkassé very probably from Tône; and Kpélé probably from Kloto. I assumed all those were correct when assigning HASC codes. Lomé is not listed separately in my sources, so if it was ever separate from Golfe, it has probably been merged with it again. The result is as shown in the main table above.

Other names of subdivisions: 

1. Bas-Mono: Afagnan (variant)
2. Cinkassé: Sinkassé (variant)
3. Kpélé: Kpélé-Akata (variant)
4. Tandjouaré: Tandjoaré (variant)

Sources: 

1. [1] Law Creating Prefectures and Sub-Prefectures , National Assembly of Togo (retrieved 2010-10-28).
2. [2] Étude de Faisabilité des Forages Manuels au Togo , Togo Water Ministry, Lomé, 2009-10-01 (p. 24, retrieved 2010-10-28). P. 27 has a map of the pre-2009 prefectures. Some of the population figures in the table must be off by one, but it's impossible to tell which ones.
3. [3] Corinne Sorin's thesis  on swine plague in Togo, dated 2002, has region and prefecture maps on pp. 24-25, and even some canton maps (retrieved 2010-11-06).
4. [4] Les Cantons du Togo  has a list of regions, prefectures, and cantons.
5. [5] Togo Confidentiel  (retrieved 2004-01-19).
6. [6] Togo's Direction Générale de la Statistique et de la Comptabilité Nationale  (retrieved 2007-11-17 from a different URL).