Nairobi, Jan. 27 -- So, one fine morning, you walk into the office, open your email and are confronted with a message from the Kenya Revenue Authority (KRA), informing you that you conducted some business and now owe tax on it.

You trying to recall which transaction the taxman is referring to. Then it hits you: a bit of consultancy work you did on the side. A side hustle.

But do you really need to pay tax on it? You remember the client telling you they would withhold some money and remit it to KRA as tax. So why, then, is the taxman still knocking?

Welcome to the world of withholding tax - a form of income tax that KRA says it has used to unearth 392,162 companies and wealthy individuals owing about Sh759.7 billion in unpaid taxes.

Th...