Valid classification in taxation
It is true that the uniformity essential to the valid exercise of the power of taxation does not require identity or equality under all circumstances, or negate the authority to classify the objects of taxation.
The classification made in the exercise of this authority, to be valid, must, however, be reasonable and this requirement is not deemed satisfied unless: (1) it is based upon substantial distinctions which make real differences; (2) these are germane to the purpose of the legislation or ordinance; (3) the classification applies, not only to present conditions, but, also, to future conditions substantially identical to those of the present; and (4) the classification applies equally all those who belong to the same class. (G.R. No. L-22814)