With the effect from January 1st 2015, there is a new obligation resulting from the Tax Code, that requires a certain documents of a specific form to be submitted electronically only – as a data message. It relates to the cases, when the entity or its representative has a data box established or, when the entity has a legal obligation to have its Financial Statements audited. A complete list of the certain documents can be found under the following link: http://www.financnisprava.cz/assets/cs/prilohy/fs-organy-financni-spravy/Seznam-podani-dle-74-odst-4_DR.pdf. This new obligation extends the range of the entities that will be obliged to communicate with the Financial authorities in the electronic way. The data message should be sent in a prescribed form and structure using e.g. an available application called „The electronic filling for the Financial Governance", or using the data mailbox. Should this obligation be breached, the taxpayer could get a penalty in the amount of CZK 2,000. However, if breaching of this obligation causes major problems in the process of the tax administration, the tax authority might set the penalty up to CZK 50,000. At this point, it should be emphasized, that the fine can be imposed on the entities, that have established their data box mandatory, as well as on those, who have established it voluntarily. In the Czech Republic, there are around 633 thousand operated data boxes and almost 125 thousand of them are established voluntarily. These are mainly the data boxes of the individuals. It is especially the employees with the data boxes who file the Tax Returns by themselves, who should be aware of this fact. The same goes to the employees, who are obliged to the "Solidarity tax" – employees, whose income exceeds the amount of 48times the average wage.