The Legal Electronic Data Exchange Standard is a set of two file format specifications intended to standardize bill/invoice data transmitted electronically ("e-billed") from a law firm to a corporate client. It is abbreviated LEDES, and usually pronounced as "leeds".

LEDES was developed by the LEDES Oversight Committee, which was led by PricewaterhouseCoopers. Members of the committee include law firms, corporate legal departments, electronic billing vendors and time and billing software vendors.

The file format has several variations:

• LEDES 1998B, a pipe-delimited plain text file. It is by far the more commonly used format. It lacks some flexibilty, having a rigid structure. Another disadvantage of LEDES 1998B is that invoice-level data is repeated on every line item even though it is only needed once, as it does not vary per line. Many clients attempt to impose nonstandard customizations, thus defeating the purpose of having a standard.
• LEDES 1998B International, a pipe-delimited plain text file. This file format was designed to accommodate legal bills generated outside of the United States. Released in February of 2005 by the Legal IT Innovators Group (LITIG) and the LEDES Oversight Committee (LOC), the new standard unified U.S. and U.K. file formats for the purpose of exchanging electronic invoice data.
• LEDES 2000, an XML format. Adoption of this newer standard has been slow. One advantage of LEDES 2000 is that although the structure is very well defined, the specification defines "extend" segments, allowing the insertion of client-specific fields without breaking the format or violating the standard.

Many clients using LEDES use Uniform Task-Based Management System, a line item classification system.

External link

• LEDES.org "The Standard in Legal E-billing"