2. Is the right given to the tax authorities by the Tax Administration Law to determine how much tax to pay equal to the right to set how much tax to pay compulsorily (because tax is compulsory)? Of course, according to what you said, if your turnover is really only about 1000, it should be tax-free. It can be argued and adjusted according to the actual situation. The reason is to fully prove that your monthly turnover can't reach the threshold, and it is best to provide a ledger. If the tax authorities do not adjust the compulsory tax, they may apply to the competent tax authorities for reconsideration. However, according to the relevant provisions of the Administrative Procedure Law, you must pay the tax of the current month before reconsideration. If you are dissatisfied with the reconsideration result, you can bring an administrative lawsuit to the court.
3. You can apply to the tax bureau to set up account books and truthfully declare and pay taxes.