Self Assessment Online: support for software developers

Technical specifications for software developers working with the Self Assessment Online service.

Self Assessment technical specification documents for 2014 to 2016 are now archived. For support for current and archived specifications, contact the Software Developers Support Team:

Generic technical specifications

Local Test Service

  1. Local Test Service and LTS update manager

Individual returns

Partnership returns

Trust and estate returns

Identical returns guidance

Published 1 January 2014
Last updated 20 January 2015 + show all updates
  1. Self Assessment technical support 2015 published.
  2. First published.