The first reason why one should pay the taxes diligently is because it is obligatory under the law. Another reason why one must pay the taxes regularly is to avoid the risk of being charged heavy penalty. In case you do not file the return on due date , the Income Tax department has the right to charge you interest at 1% per month from the due date to the date you actually file the return. The amount will be calculated on the tax payable by you as reduced by Tax Deducted at source (TDS) on your income and any advance tax paid by you. The same obligation applies to each year for which a person has not filed the return. In case the tax has been paid but a return has not been filed, then the income tax authorities may levy a penalty of Rs 5000 for the same. Some countries also take into account the proof of filling your income tax returns while issuing visa to a person. The Income Tax department is reassured of the financial stability of the institution if it has filed its return without any interruption.