Catherine specialises in information technology law and in particular, e-commerce, electronic data interchange and data protection. In addition, Catherine regularly advises clients in the aviation sector on a broad range of corporate and commercial matters including IT, e-commerce, EU Regulation and intellectual property.

Catherine's IT and e-commerce's practice is ranked in the top tier by the edition 2002 of EURO LEGAL 500 with the following comments:" Bird & Bird traditional UK strengths in IT and E-commerce are also apparent in its Brussels office.  Partner Catherine Erkelens heads a talented team acting for IT service providers, software developers and advising non-IT clients on IT-related issues. Expertise covers service level agreements, outsourcing, technical contracts, as well as e-commerce issues like e-payment problems, domain names and encryption."

Her experience in IT and E-commerce EU regulatory law has been recognized by the 2001 and 2002 editions of EURO LEGAL 500: " Leading players include Bird & Bird, particularly partner Catherine Erkelens"