Simply put - you have paid several types of taxes over the past few years. You may have received tax benefits and did not claim them. It is possible that your tax adjustment was made at the beginning of the year based on an estimate, but the estimate was not accurate, and you were actually charged tax on money you did not earn. In short, it is very possible that you have been charged an excess tax. This tax, after a new calculation and a request, is returned by the tax authority. with interest!