International Territorial Level (ITL) is a geocode standard for referencing the subdivisions of the United Kingdom for statistical purposes, used by the Office for National Statistics (ONS). From 2003 and until 2020 it functioned as part of the European Union and European Statistical System's geocode standard Nomenclature of Territorial Units for Statistics or NUTS.
Following Brexit, the ONS set to develop a domestic statistical classification framework separate from NUTS. Currently, the ITLs are a mirror to the pre-existing NUTS system, they retain the same three level hierarchy and boundaries used for NUTS in the United Kingdom since 2018, with the next review scheduled for 2024. ITLs are set to follow a similar review timetable to NUTS, being reviewed every three years. The ONS will develop new official GSS codes of ITL geography aligned with the existing NUTS codes. From 1 January 2021, the ONS encourages "ITL" be used as a replacement to the "NUTS" designation, with lookups between NUTS and ITL maintained and published until 2023.
The current ITL classification is a mirror of the previous NUTS classification with slight modification, the ONS lists 12 regions at ITL 1, 41 regions at ITL 2, and 179 regions at ITL 3. "UK" in the NUTS codes were replaced with "TL".
The last NUTS classification is dated 21 November 2016 and was effective from 1 January 2018, listed 12 regions at NUTS 1, 40 regions at NUTS 2, and 174 regions at NUTS 3 level.
The 12 ITL regions of the United Kingdom are listed below. Population numbers are for mid-2019 (as NUTS 1), and areas are in square kilometres. Data is from the Office for National Statistics.
In the first version in 2003, North Eastern Scotland (which then included part of Moray) was coded UKM1, and Highlands and Islands was coded UKM4.
The codes in this scheme start with "UKC" to avoid confusion with codes in the previous system, which identified 11 regions of England using codes that started with "UK1" through "UK9" plus "UKA" and "UKB".
NUTS 2006 came into force on 1 January 2008.
NUTS 2010 came into force on 1 January 2012.
2010 changes to NUTS 2 also resulting in changes with NUTS 3 regions
2010 changes to NUTS 3 areas without changes occurring to NUTS 2 areas
NUTS 2013 came into force on 1 January 2015.
2015 changes to NUTS 3 areas without changes to NUTS 2 areas:
In 2015 the Greater London NUTS 1 area was left unchanged however the previous NUTS 2 area of inner and outer London were abolished and with the previous NUTS 3 areas becoming NUTS 2 areas. Thus NUTS 2 of Inner London West UKI11 becoming the NUTS 3 area of UKI3 and likewise: Inner London East (from UKI12 to UKI4), Outer London East and North East (from UKI21 to UKI5), Outer London South (from UKI22 to UKI6) and Outer London West and North West (from UKI23 to UKI7). The NUTS 3 areas are now a single or a group of two or three boroughs.
Following Brexit, the classification used by the ONS was replaced with ITLs. Between 2021 and the next review scheduled for 2024, the ITLs are a mirror of the NUTS classification adopted in 2018. All NUTS codes containing "UK" were changed to use "TL" for Territorial Level.
Below the ITL levels, the two LAU (Local Administrative Units) levels are:
The two LAU levels are maintained by the UK Office for National Statistics within the ONS coding system.
The LAU codes of the United Kingdom can be downloaded here: