The penalty for late filing of income taxes can vary based on several factors, such as the country and tax regulations. In the United States, for example, the penalty for the late filing of federal income taxes is generally determined by the amount of tax owed and the duration of the delay. As of 2021, the penalty is 5% of the unpaid tax amount per month, up to a maximum of 25% of the unpaid tax. If the tax return is more than 60 days late, the minimum penalty is either $435 or 100% of the unpaid tax, whichever is less. Additionally, interest is charged on the unpaid tax amount until it is fully paid. It is important to note that these penalties and rules may vary, so it is always best to consult the specific tax regulations of your country or jurisdiction.