The Online Filing software enables applicants and attorneys to submit patent applications and documents to the EPO via the Internet. During the online session, the application is encrypted and sent to the filing office in a single, secure transaction. An electronic acknowledgement of receipt, containing the date and application number, is then issued to the sender. This date becomes the date of filing, without any further correspondence being necessary. This is only one of the key benefits. eOLF also provides the means to file EP, national office and PCT patent applications using the same product.