ETSI TC-LI is an important committee in the world of Lawful Interception. The specifications it publishes have become the de facto standards throughout the world.


The ETSI TC-LI committee has three plenary meetings per year. At a plenary meeting, delegates can officially submit change requests to existing specifications. Additionally, new ideas and requirements are regularly discussed.

If there are specific topics that require more in-depth discussion, the committee organizes specific rapporteur meetings at which the rapporteurs of specifications and interested delegates join to have deep technical discussions.

Delegates in TC-LI represent LEAs, CSPs, network vendors and lawful interception vendors.

Ongoing work

ETSI TC-LI is currently working on the following topics:

  • Extensions of ETSI TS 102 232-2 in the area of Messaging Services
  • An improved data structure for Lawful Disclosure
  • Handover for messaging services over HTTP/XML instead of using the ETSI TS 102 232 ASN.1 based approach

Published specifications

ETSI TS 102 232: Lawful Interception

The de facto LI specification that details the HI2 and HI3 interfaces.

Read more about it in our EVE explains article on ETSI TS 102 232.

ETSI TS 103 120: Warrant exchange

Defines an electronic interface for HI1, the process used for the exchange of warrant and other information between LEAs and CSPs.

ETSI TS 103 221: X1/X2/X3

Replaces the proprietary X1/X2/X3 interfaces maintained by the network vendors with a standardized approach.

Read more about it in our EVE explains article on ETSI TS 103 221.

ETSI TS 101 331: LEA requirements

CSPs that are new to Lawful Interception can find a good summary of LEA requirements in this specification. TC-LI uses this as a baseline for the other specifications it maintains.

Download the latest version from the ETSI website.

ETSI TS 102 657: Retained data

Defines the HI-A and HI-B interfaces. HI-A is used by an LEA to submit a request for retained data to a CSP. In turn, when a CSP has the requested data, it uses the HI-B interface to deliver it.

A copy can be downloaded from the ETSI website.

ETSI TS 101 671: Legacy interception

The legacy LI specification that details the interception of telephony and mobile voice services using circuit-switched networks.

Due to its legacy status, it will not be updated anymore but a copy can be downloaded from the ETSI website.