Electronic Declaration system (EDS) changed submission of tax declaration documents from paper to electronic form. In accordance with effective laws, tax returns became mandatory for almost every citizen of Lithuania starting 2004. For this reason, the number of tax returns and the need to provide the more efficient services to citizens increased, as it became more complicated for the employees of the Tax Inspectorate to fulfil their daily responsibilities. More than 90% declarations of citizens and entities (RIT, VAT and other) are filed electronically using the system. Solution is constantly improved by maintenance and development activities to support user needs, changes in legal base and to meet new technological challenges.