You need to learn basic income tax rules. It does not matter if the customers are overseas on living on Mars or the Moon, THESE PEOPLE STILL HAVE TO DECLARE THEIR INCOME. Happens in every country in the World including Australia.
Don't teach me or advising, when people in Pakistan looting the money, stuffing in such racist countries who turn deaf to the calls of returning the looting wealth.
I know many western who enjoy tax free income, while working outside their countries.
Now, miserably failed institutes of Pakistan are turning their guns to common people who find Clint themselves, get orders from them starting from 2-5 US $. All benefits and ignorance are enjoyed by elite class.
One country two system will miserably fail, if such approach continued.