| Codes | Counties | Codes | Counties | Codes | Counties | Codes | Counties | 
|---|---|---|---|---|---|---|---|
| 1 | Mombasa | 2 | Kwale | 3 | Kilifi | 4 | Tana River | 
| 5 | Lamu | 6 | Taita-Taveta | 7 | Garissa | 8 | Wajir | 
| 9 | Mandera | 10 | Marsabit | 11 | Isiolo | 12 | Meru | 
| 13 | Tharaka-Nithi | 14 | Embu | 15 | Kitui | 16 | Machakos | 
| 17 | Makueni | 18 | Nyandarua | 19 | Nyeri | 20 | Kirinyaga | 
| 21 | Murang'a | 22 | Kiambu | 23 | Turkana | 24 | West Pokot | 
| 25 | Samburu | 26 | Trans-Nzoia | 27 | Uasin Gishu | 28 | Elgeyo-Marakwet | 
| 29 | Nandi | 30 | Baringo | 31 | Laikipia | 32 | Nakuru | 
| 33 | Narok | 34 | Kajiado | 35 | Kericho | 36 | Bomet | 
| 37 | Kakamega | 38 | Vihiga | 39 | Bungoma | 40 | Busia | 
| 41 | Siaya | 42 | Kisumu | 43 | Homa Bay | 44 | Migori | 
| 45 | Kisii | 46 | Nyamira | 47 | Nairobi |