all the four must match
but to some situations may be Thailand has other principles
The subjects or citizens ought to contribute to the support of the government as nearly as possible in proportion to their respective abilities -- that is, in proportion to the revenues which they enjoy under its protection
That is one like your father pays tax from his salary every month. The principle of certainty says that;; 2nd. The tax which each individual is bound to pay ought to be certain, and not arbitrary. The time and manner of payment and the sums to be paid ought to be plain to the contributors and everybody else. Otherwise they are placed more or less in the power of the tax-gatherer, who may use it for oppressive purposes. you can understand that your father know how much he pays as tax every month because there is a pay slip that analyses his salary and all other contribution The Principle of convenience says that:Every tax ought to be levied at the time and in the manner in which it is most likely to be convenient for the contributors to pay it. This is one great advantage in indirect taxation, as the purchaser of an article upon which it has been assessed, can buy or not, when or to what amount, be pleases like your father, he pays tax at the end of the month when he has his salary. he cannot pay tax when he doesn't have money The principle of profitability says that:: Every tax ought to be so contrived as to take out and keep out of the pockets of the people as little as possible above what it brings into the public treasury. In other words, it should be collectable at a minimum of expense here people who collect the tax should not have salary more than the income from the tax
Government officers who are responsible to collect the tax, have salary less than the tax income, so the tax collection is a good principle