This is the official service of STC (State Tax Committee), the most accessible service for receiving and transmitting electronic invoices. The service is synchronized with the roaming operator, which provides the centralized storage of the invoices as well as the transmission of primary documents between operators. At the moment, it receives and transmits such types of documents as invoices and its subtypes (about 5), acts, powers of attorney, and also allows you to exchange documents in PDF format only within this program. It has an integration with other accounting systems based on the 1C: Enterprise products, billing systems, etc., which allows you to directly send and receive documents to the site without entering them manually, as well as the ability to group upload documents using the Excel template. All documents are signed using EDS keys (electronic digital signature) that are equal to paper documents.