Lega tax loopholes permissable

Slms a persons wage is suppose to be 1600 a month but to avoid paying tax they pay themselves 1000 pound wage and plan to pay the remaining as shares/bonuses in the company at the end of the year so they dont pay tax- is this permissable in islam?

To clarify:
If there intention is to do the above to avoid paying tax is it permissable.
Or
If there intention is to do the above to pay less tax is it permissable.

Pls advise