When Bulgaria joined the European Union in 2007 the National Library was included in the TELplus Project (eContentPlus Programme of the European Commission), coordinated by the European Library Office (KB – the National Library of the Netherlands). TELplus was a targeted project for libraries that was supported by CENL. The European Library is a service, managed by KB on behalf of CENL. At different stages this service is funded by the European Commission.
From 2007 to 2009 the National Library had to submit to the European Library the National Catalogue of the Bulgarian Literature and the Digital Library (including required full changes of the system (portal, entrance etc.), identification and description of the collection that have to be included, Metadata standartization, testing the access to the library collections, translation of the portal interface in Bulgarian and preparation of a marketing and communication plan).