Income Tax

I have always known that we need to pay income tax once we start to earn income. Though I was always wondering why I don't have to pay when I was working part-time.

Today while revising on the chapter of Income Tax, I remembered one interesting point which was brought into discussion during the last lecture by Mr. Sonny. The matter of dual taxing and income from abroad.

Dual taxing basically refers to that you are only required to pay income tax in one country. Mr. Sonny gave a good example during the class, where he is from Indonesia, yet he pays income tax to the Malaysian Government and since he has paid his income tax in Malaysia, a certain law protects him from being taxed again by the Indonesian Government. Then this intrigued me somehow, how do we know or do we get to choose to whom we would like to pay the income tax to? After a short discussion earlier today, I still don't really have a definitive answer, but one thing is for sure, we do not get to pay in favour of our choice, and one example given that if you own two companies, one in Singapore and the other in Malaysia, and both are earning approximately the same profit/revenue in USD, in this case, we would most likely need to pay our income tax to the country of our residential.

Another interesting fact I learned in the recent classes is that we are not taxed by the Malaysian Government for overseas income. One simple example is that when you invest in overseas, and you receive your yearly dividend, that amount of dividend shall not be counted in to your AGGREGATE INCOME. This leads me to another intriguing question, if we received a project, and it needs to be performed in overseas(though we still have projects locally, but this overseas project earns double the usual profit), will this be tax? If the project last less than six months, or when the project last more than one year, to whom are we taxed and are we obliged to pay?