Please don't forget that in Malaysia, personal income tax is on the self assessment since 2005 (a brilliant strategy from the IRB).

What this means is that ALL the responsibility for knowing what are the taxable income, when n how to compute the tax n the reporting of it, and the payment of the tax payable is done by the Malaysian tax payer! So later on, if the IRB finds errors or omissions, these will all be errors or omissions deemed deliberately done by the tax payer. So penalties in addition to back taxes!

Previously it was the responsibility for the IRB officer to go through your return, n he determined the tax payable.