HM Revenue & Customs (HMRC) are making a security update to their system which means that from 21 February 2022 you must be using Sage Corporation Tax v3.4.1 or above to make CT600 submissions from your software.

You may currently be using an earlier version of Sage Corporation Tax and you must check that your software is up to date as soon as possible to avoid any disruption to your submissions.

You can check your version number by opening Sage Corporation Tax and clicking Help, then clicking About Sage Corporation Tax, then scroll to the top of the page.

You can find help to update your software in our quick guide to downloading and installing your update.