Illegal. The online website of residential inquiry shows that the collection of farmland occupation tax is in the face of the phenomenon of indiscriminate occupation of farmland before, which does not mean that farmland can be occupied for building houses after paying farmland occupation tax. It is illegal to build houses on cultivated land, which will be judged as illegal buildings according to law, and most of these buildings will face fines and penalties for demolition. Therefore, it is illegal to pay farmland occupation tax for building houses.