If one avoids paying income tax every year, and left the country, is it a sin not paying income tax?

Praise be to Allah, the Lord of the World; and may His blessings and peace be upon our Prophet Muhammad and upon all his Family and Companions.

Escaping from paying liable taxes is not permissible. Liable taxes means the taxes imposed by a ruler on those who live in his state without exceeding the proper limits set by Sharia.
On the other hand, if the taxes are not legal then one may escape from paying them since they are considered among forbidden tolls and eating the people's money unjustly.
There are many conditions when they meet, the taxes imposed by a government become legitimate:
1) The government treasury becomes empty.
2) The taxes should be imposed only on the capable leaving those who are incapable.
3) There should be a real necessity to impose such taxes. Whenever the government is in a position to fulfill its necessity from any other sources then imposing taxes on the people becomes forbidden.
4) The taxes should be limited only to the time of necessity.
5) They should be imposed justly on all categories of a society.
6) Finally there should not be any violation or misuse of the public money.
Allah knows best.