The main purpose of a TEI Workgroup is to formally recommend extensions or modifications to the TEI Guidelines. The following workgroups are currently under active under the aegis of the TEI Council: Personography Workgroup Chartered in January 2006; chaired by Matthew Driscoll. Physical Bibliography Workgroup Chartered in May 2004; chaired by Murray McGillivray.

The following workgroups have concluded their activity: Character Encoding Workgroup Chaired by Christian Wittern; completed its recommendations in January 2005. Metalanguage Workgroup Tasked to produce recommentatiosn on the XML vocabulary and other mechanisms used to encode the Guidelines. Chaired by Sebastian Rahtz; completed tasks in February 2005. Migration Workgroup Tasked to produce recommendations on conversion of legacy TEI data from SGML to XML. Chaired by Chris Ruotolo; completed tasks in January 2005. Stand-Off Markup Workgroup Chaired by David Durand. Manuscript Description Task Force Completed December 2005.