Kenya is one of the jurisdictions in the world that operate a self-assessment tax administration regime. Primarily, this kind of regime is purely based on trust; the taxman trusts that the declarations of income made by taxpayers are a true reflection of the income generated.
At a secondary level, the taxman may issue an assessment as well as other remedial measures stipulated in the law in case there is suspicion of under-declaration of income by a given taxpayer.