The lecture will be devoted to the long-term archiving of electronically signed documents. Even in the digital future, the same security standards as in the paper past must apply. Digital documents must be able to withstand communication with another company or office, even in the event of a possible lawsuit in the future. This will ensure a qualified electronic signature issued by a qualified trusted service provider. But if we want to ensure the long-term verifiability of the document, the electronic signature alone is not enough. The basis for extending the verifiability of documents with an electronic signature is the so-called an electronic time stamp that extends it by five to six years. As a rule, it is added to the document at the same time as the electronic signature and the so-called archival electronic signature. If this time is not sufficient, it is necessary to continuously "treat" the documents and add additional time stamps and so-called validation data. The document that we create by creating this data always has a defined structure (LTA formats) in order to make it possible, e.g. using Adobe, verify at any time. One option that solves the long-term verifiability of an electronic document is the I.CA LTA service (https://www.ica.cz/lta-komponenty).