Banks, being under tremendous market competition pressure, are interminably engaged in exploring new bank products and suitable distribution channels. And yet, the developed new products and distribution channels can not be marketed without adequate and reliable IT support. Consequently, the heaviest innovation burden in banking industry lays on the information technology which is already excessively engaged in maintaining and integrating the existing heterogeneous subsystems. Traditional development technologies and methods have not proved to be particularly successful in solving these interlaced problems. Apparently, we need new approaches to these issues which would allow reconciliation of the constantly developing subsystems following the growing market demands and regulatory changes with the requirement for subsystems tight integration. XML technology is definitely one of the possible approaches to these problems which will have strong impact on the development of bank information systems in the following years. XML has already been proved world-wide as a data exchange standard in e-business transactions and, if applied, it would also free a significant portion of our resources which are now engaged in development and maintenance of the data exchange systems. All appraisals show that by the end of the year 2003 the number of communication mobile devices (telephones, notebooks, palms, terminals etc.) used by Internet clients will exceed the number of personal computers. Maintenance of an Internet Banking system covering such a large range of client devices would be a very onerous task. XML, having the ability to separate data from the presentation definition, is proving to be the best solution for data capturing from the same source and their transformation to a text format adjusted for displaying on a client which was used to access the system. Also, XML is suitable for developing intranet applications for searching and analysing business information, e.g. personal bankers supporting application. Among XML applications the most is expected from the XBRL which has been adopted by the leading financial, consultant and audit companies world-wide. As an alternative to the exhausting and long-lasting analysis of the client’s financial statements data can be captured in the XBRL format directly from their financial applications, accelerating the process of the client’s financial position determination.