Is avoiding tax moral?

Is it moral to avoid tax? Is it moral not to pay tax when everyone else has to... Many big cooperation's here in the Uk are avoiding paying their taxes.. tax avoidance is legal but tax evading is illegal.. but if you ask me both are just about the same thing only the tax avoiders are within the law. Some one once questioned me on another blog saying that finding loop holes in the tax system is moral as these loopholes have been set up by the government for this to happen.. which sounds like plutocracy to me as simply only the big business can go abroad to avoid tax not the small ones.

If it was up to me i would ban big business form doing business if they are avoiding paying tax whether it is legal or not!

Taxes go towards healthcare and other much needed services if everyone was able to avoid paying tax what sort of country would we live in?