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Guidance: Corporation Tax: service availability and issues

  • 31 January 2022

    Planned downtime from 8pm to midnight on Wednesday 2 February 2022 has been added.

  • 14 January 2022

    Planned downtime from 8am to 10am Saturday 22 January 2022 has been added.

  • 2 December 2021

    Planned downtime from 5pm on Friday 3 December 2021 to 9am on Monday 6 December 2021 has been added.

  • 10 November 2021

    Planned downtime from 5pm on Friday 12 November 2021 to 9am Monday 15 November 2021 has been added.

  • 5 November 2021

    A service issue about submitting company tax returns due to legislation introduced in the 2021 Spring Budget has been added.

  • 14 October 2021

    Planned downtime from 5pm on Friday 15 October 2021 to 9am Monday 18 October 2021 has been added.

  • 7 October 2021

    A service issue about maintenance to the Companies House e-filing system has been added.

  • 4 October 2021

    Planned downtime from 11:59pm on Monday 4 October 2021 to 12:30am Tuesday 5 October 2021 has been added.

  • 1 October 2021

    Planned downtime from 12pm to 12:30pm on Tuesday 5 October 2021 has been added.

  • 29 September 2021

    Planned downtime from 12pm to 8pm on Wednesday 6 October 2021 has been added.

  • 26 August 2021

    Service issues message explaining that returns filed for accounting periods ending after 31 March 2021 will generate an error has been added.

  • 4 August 2021

    Planned downtime for the Company Accounts and Tax Online service from 5pm on Friday 6 August 2021 to 9am Monday 9 August 2021 has been added.

  • 4 August 2021

    Planned downtime from 5pm on Friday 6 August 2021 to 9am Monday 9 August 2021 has been added.

  • 1 July 2021

    The service issue about Research and Development claims has been resolved.

  • 11 May 2021

    Planned downtime for the free online filing service from 5pm on Friday 14 May 2021 to 9am Monday 17 May 2021 has been added.

  • 14 April 2021

    Planned downtime message for the free online filing service from 5pm Friday 16 April 2021 to 9am Monday 19 April 2021 has been added.

  • 1 April 2021

    Service issue for Research and Development claims added.

  • 24 March 2021

    Planned downtime from 5pm on Wednesday 24 March 2021 to 9am on Thursday 25 March 2021 has been added.

  • 18 March 2021

    The planned downtime from 5pm on Friday 19 March 2021 to 9am on Monday 22 March 2021 has been cancelled.

  • 17 March 2021

    Planned downtime from 5pm on Friday 19 March 2021 to 9am on Monday 22 March 2021 has been added.

  • 4 March 2021

    Planned downtime from 5pm on Friday 5 March 2021 to 9am Monday 9 March 2021 has been added.

  • 17 February 2021

    Planned downtime from 8am to 10am on Saturday 20 February 2021 has been added.

  • 12 February 2021

    Updated planned downtime message for Saturday 13 February 2021 – the free online filing service will be unavailable from 8am to 2pm on Saturday 13 February 2021.

  • 11 February 2021

    Planned downtime from 8am to 2pm on Saturday 13 February has been added. Companies using the HMRC free filing service (CATO) wishing to joint file or file accounts to Companies House may be affected. HMRC submissions are unaffected and the service will be available during the maintenance period.

  • 24 December 2020

    Planned downtime from 7pm on Thursday 31 December 2020 to 7am on Friday 1 January 2021 has been added.

  • 26 June 2020

    The service issues for ‘Changes to the Corporation Tax main rate’ and ‘Annual rate increase for Structures and Buildings Allowance’ have been removed.

  • 19 June 2020

    Guidance has been updated to advise if you need to file your Company Tax Return before July 2020 and need to apply the new rules, contact the Corporation Tax helpline.

  • 18 June 2020

    The HMRC free filing service (CATO) will be updated for companies that will be, or are already, subject to the off-payroll rules by July 2020.

  • 3 June 2020

    The HMRC Corporation Tax online service will now be updated for the revised rate of 19% by the last week in June 2020.

  • 7 May 2020

    The revised rate of 19% should be applied to this service by the second week of July

  • 8 April 2020

    Service issues updated with information about changes to the Corporation Tax main rate, Structures and Building Allowance annual rate and off-payroll working rules.

  • 27 March 2020

    Updated to confirm the off-payroll working legislation for the private sector has been deferred until 6 April 2021.

  • 19 February 2020

    The contact email address for advice about off-payroll working rules has been updated.

  • 14 February 2020

    The Marginal Rate Relief calculator will be unavailable from 6pm to 8pm on Sunday 16 February 2020. Information about this issue has been added.

  • 6 February 2020

    The service issues have been updated with information about off-payroll working rules for the private sector.

  • 25 November 2019

    Planned downtime that was scheduled from 9pm on 25 November 2019 to 6am on 26 November 2019 has been changed. The service will now be unavailable from 9pm on 26 November 2019 to 6am on 27 November 2019.

  • 22 November 2019

    Information about maintenance for setting up a direct debit between 9pm on Monday 25 November 2019 to 6am on Tuesday 26 November 2019 has been added.

  • 19 November 2019

    This service will be unavailable from 9pm on Thursday 21 November to 6am on Friday 22 November 2019. Information about this issue has been added.

  • 12 November 2019

    Planned downtime for 9pm on 12 November 2019 to 6am on 13 November 2019 has been added.

  • 12 November 2019

    Planned downtime for 9pm on 12 November 2019 until 6am on 13 November 2019 has been cancelled.

  • 12 November 2019

    Planned downtime from 9pm on 12 November 2019 until 6am on 13 November 2019.

  • 11 November 2019

    You will be unable to use the ‘view liabilities and payments’ and the ‘view and amend contact details’ part of the service from 9pm on Monday 11 November 2019 to 6am on Tuesday 12 November 2019. Information about this has been added.

  • 8 November 2019

    The service issue ‘Companies House filing’ has been added.

  • 4 November 2019

    The service issue about changes that may affect your company tax return has been updated.

  • 25 October 2019

    The ‘Changes that may affect your company tax return’ service issue has been updated with more information on submitting a Structures and Buildings Allowance claim online before April 2020.

  • 18 October 2019

    The service issue about filing to Companies House has been updated.

  • 17 October 2019

    A service issue about filing to Companies House has been added.

  • 17 October 2019

    The service issue about filing to Companies House has been removed.

  • 14 October 2019

    A service issue about filing to Companies House has been added.

  • 14 October 2019

    A service issue about changes that may affect your company tax return has been added.

  • 3 October 2019

    The service issue ‘Filing using the Companies House system’ has been removed.

  • 3 October 2019

    A service issue about filing using the Companies House system has been added.

  • 2 July 2019

    The service issue about the temporary increase in Annual Investment Allowance has been resolved.

  • 18 June 2019

    Information about the service issue for the temporary increase in the Annual Investment Allowance has been amended, to show the Corporation Tax online service will be updated at the end of June 2019.

  • 7 December 2018

    A service issue about a temporary increase in Annual Investment Allowance has been added.

  • 16 November 2018

    Downtime previously planned for 17 and 18 November will now take place on 24 and 25 November.

  • 14 November 2018

    Planned downtime for Wednesday 14 November 2018 9:15pm to 2:45am on Thursday 15 November 2018 has been added.

  • 8 November 2018

    Service issue for Thursday 8 November 2018 from 6pm to 11pm has been added.

  • 1 November 2018

    Planned downtime for 3 and 4 November will now take place on 17 and 18 November.

  • 25 October 2018

    Planned downtime for 3 and 4 November added.

  • 22 March 2018

    An Issue about submissions on 19 March 2018 and 20 March 2018 has been added to the page.

  • 19 March 2018

    The service issues section has been updated.

  • 4 January 2018

    A message about some customers experiencing technical difficulties and delayed submission responses has been added to the page.

  • 12 December 2017

    Service availability section updated.

  • 8 December 2017

    The service issues section has been updated.

  • 2 November 2017

    There is a service availability issue causing delayed submission responses.

  • 1 November 2017

    A service issue message about HMRC’s Corporation Tax free filing software has been added.

  • 30 August 2017

    The ‘Changes that may affect your Company Tax Return – Loss reform’ section has been amended with new information about filing your return.

  • 21 July 2017

    The CT600 Return submission problem has been resolved.

  • 18 July 2017

    The service issues section has been updated.

  • 14 July 2017

    CT600 Return submission problem has now been resolved.

  • 13 July 2017

    The service issues section has been updated.

  • 11 July 2017

    The service issues section has been updated.

  • 1 June 2017

    The ‘Service issues’ section has been updated.

  • 17 May 2017

    The ‘Service issues’ section has been updated.

  • 4 May 2017

    The service issues message about the Corporation Tax online return service – returns with an accounting period ending after 31 March 2017 has been updated as the problem is now resolved.

  • 13 April 2017

    New message at ‘Service issues’ added due to online problems with the CATO service.

  • 6 April 2017

    This guidance has been updated to show latest service issues.

  • 9 March 2017

    Information regarding HMRC’s joint filing service and free filing services for Company Tax Returns has been updated.

  • 21 December 2016

    Information regarding HMRC’s free filing service for company tax returns has been updated.

  • 13 October 2016

    The routine renewal of Adobe CT600 Trusted certificate section has been updated to reflect the renewal of the embedded certificate.

  • 31 August 2016

    Spring Budget 2016 content removed

  • 30 August 2016

    Agents unable to log in to their online account issue updated to show the problem has now been resolved.

  • 30 August 2016

    The service issues section has been updated to remove the HM Revenue and Customs online filing software – computations trading losses summary page issue.

  • 24 August 2016

    The ‘Agents unable to log in to their online account’ message has been updated.

  • 11 August 2016

    A service issue message has been added to the page.

  • 7 July 2016

    The Spring Budget 2016: changes that may affect your Company Tax Return section has been updated.

  • 26 April 2016

    ‘Error 9316/9965 using HM Revenue and Customs/Adobe return’ paragraph added to the page under service issues.

  • 21 April 2016

    Removal of ‘Changes that may affect your Company Tax Return’ section.

  • 14 April 2016

    Service issues section has been updated.

  • 12 April 2016

    The service issues section has been updated with information about essential maintenance for Companies House online services.

  • 21 March 2016

    The service issues section has been updated with information from the Spring Budget 2016 about
    changes that may affect your Company Tax Return.

  • 13 January 2016

    Important changes to HMRC’s free filing service for company tax returns

  • 24 December 2015

    Service issues section has been updated.

  • 15 December 2015

    Routine renewal of Adobe CT600 Trusted certificate message added to the page.

  • 24 September 2015

    Planned downtime has been added to this page.

  • 22 September 2015

    Downtime for Corporation Tax online service has been added to this page.

  • 2 September 2015

    Latest updates on creating a new Government Gateway account.

  • 24 August 2015

    First published.

  • 31 January 2022

    Planned downtime from 8pm to midnight on Wednesday 2 February 2022 has been added.

  • 14 January 2022

    Planned downtime from 8am to 10am Saturday 22 January 2022 has been added.

  • 2 December 2021

    Planned downtime from 5pm on Friday 3 December 2021 to 9am on Monday 6 December 2021 has been added.

  • 10 November 2021

    Planned downtime from 5pm on Friday 12 November 2021 to 9am Monday 15 November 2021 has been added.

  • 5 November 2021

    A service issue about submitting company tax returns due to legislation introduced in the 2021 Spring Budget has been added.

  • 14 October 2021

    Planned downtime from 5pm on Friday 15 October 2021 to 9am Monday 18 October 2021 has been added.

  • 7 October 2021

    A service issue about maintenance to the Companies House e-filing system has been added.

  • 4 October 2021

    Planned downtime from 11:59pm on Monday 4 October 2021 to 12:30am Tuesday 5 October 2021 has been added.

  • 1 October 2021

    Planned downtime from 12pm to 12:30pm on Tuesday 5 October 2021 has been added.

  • 29 September 2021

    Planned downtime from 12pm to 8pm on Wednesday 6 October 2021 has been added.

  • 26 August 2021

    Service issues message explaining that returns filed for accounting periods ending after 31 March 2021 will generate an error has been added.

  • 4 August 2021

    Planned downtime for the Company Accounts and Tax Online service from 5pm on Friday 6 August 2021 to 9am Monday 9 August 2021 has been added.

  • 4 August 2021

    Planned downtime from 5pm on Friday 6 August 2021 to 9am Monday 9 August 2021 has been added.

  • 1 July 2021

    The service issue about Research and Development claims has been resolved.

  • 11 May 2021

    Planned downtime for the free online filing service from 5pm on Friday 14 May 2021 to 9am Monday 17 May 2021 has been added.

  • 14 April 2021

    Planned downtime message for the free online filing service from 5pm Friday 16 April 2021 to 9am Monday 19 April 2021 has been added.

  • 1 April 2021

    Service issue for Research and Development claims added.

  • 24 March 2021

    Planned downtime from 5pm on Wednesday 24 March 2021 to 9am on Thursday 25 March 2021 has been added.

  • 18 March 2021

    The planned downtime from 5pm on Friday 19 March 2021 to 9am on Monday 22 March 2021 has been cancelled.

  • 17 March 2021

    Planned downtime from 5pm on Friday 19 March 2021 to 9am on Monday 22 March 2021 has been added.

  • 4 March 2021

    Planned downtime from 5pm on Friday 5 March 2021 to 9am Monday 9 March 2021 has been added.

  • 17 February 2021

    Planned downtime from 8am to 10am on Saturday 20 February 2021 has been added.

  • 12 February 2021

    Updated planned downtime message for Saturday 13 February 2021 – the free online filing service will be unavailable from 8am to 2pm on Saturday 13 February 2021.

  • 11 February 2021

    Planned downtime from 8am to 2pm on Saturday 13 February has been added. Companies using the HMRC free filing service (CATO) wishing to joint file or file accounts to Companies House may be affected. HMRC submissions are unaffected and the service will be available during the maintenance period.

  • 24 December 2020

    Planned downtime from 7pm on Thursday 31 December 2020 to 7am on Friday 1 January 2021 has been added.

  • 26 June 2020

    The service issues for ‘Changes to the Corporation Tax main rate’ and ‘Annual rate increase for Structures and Buildings Allowance’ have been removed.

  • 19 June 2020

    Guidance has been updated to advise if you need to file your Company Tax Return before July 2020 and need to apply the new rules, contact the Corporation Tax helpline.

  • 18 June 2020

    The HMRC free filing service (CATO) will be updated for companies that will be, or are already, subject to the off-payroll rules by July 2020.

  • 3 June 2020

    The HMRC Corporation Tax online service will now be updated for the revised rate of 19% by the last week in June 2020.

  • 7 May 2020

    The revised rate of 19% should be applied to this service by the second week of July

  • 8 April 2020

    Service issues updated with information about changes to the Corporation Tax main rate, Structures and Building Allowance annual rate and off-payroll working rules.

  • 27 March 2020

    Updated to confirm the off-payroll working legislation for the private sector has been deferred until 6 April 2021.

  • 19 February 2020

    The contact email address for advice about off-payroll working rules has been updated.

  • 14 February 2020

    The Marginal Rate Relief calculator will be unavailable from 6pm to 8pm on Sunday 16 February 2020. Information about this issue has been added.

  • 6 February 2020

    The service issues have been updated with information about off-payroll working rules for the private sector.

  • 25 November 2019

    Planned downtime that was scheduled from 9pm on 25 November 2019 to 6am on 26 November 2019 has been changed. The service will now be unavailable from 9pm on 26 November 2019 to 6am on 27 November 2019.

  • 22 November 2019

    Information about maintenance for setting up a direct debit between 9pm on Monday 25 November 2019 to 6am on Tuesday 26 November 2019 has been added.

  • 19 November 2019

    This service will be unavailable from 9pm on Thursday 21 November to 6am on Friday 22 November 2019. Information about this issue has been added.

  • 12 November 2019

    Planned downtime for 9pm on 12 November 2019 to 6am on 13 November 2019 has been added.

  • 12 November 2019

    Planned downtime for 9pm on 12 November 2019 until 6am on 13 November 2019 has been cancelled.

  • 12 November 2019

    Planned downtime from 9pm on 12 November 2019 until 6am on 13 November 2019.

  • 11 November 2019

    You will be unable to use the ‘view liabilities and payments’ and the ‘view and amend contact details’ part of the service from 9pm on Monday 11 November 2019 to 6am on Tuesday 12 November 2019. Information about this has been added.

  • 8 November 2019

    The service issue ‘Companies House filing’ has been added.

  • 4 November 2019

    The service issue about changes that may affect your company tax return has been updated.

  • 25 October 2019

    The ‘Changes that may affect your company tax return’ service issue has been updated with more information on submitting a Structures and Buildings Allowance claim online before April 2020.

  • 18 October 2019

    The service issue about filing to Companies House has been updated.

  • 17 October 2019

    A service issue about filing to Companies House has been added.

  • 17 October 2019

    The service issue about filing to Companies House has been removed.

  • 14 October 2019

    A service issue about filing to Companies House has been added.

  • 14 October 2019

    A service issue about changes that may affect your company tax return has been added.

  • 3 October 2019

    The service issue ‘Filing using the Companies House system’ has been removed.

  • 3 October 2019

    A service issue about filing using the Companies House system has been added.

  • 2 July 2019

    The service issue about the temporary increase in Annual Investment Allowance has been resolved.

  • 18 June 2019

    Information about the service issue for the temporary increase in the Annual Investment Allowance has been amended, to show the Corporation Tax online service will be updated at the end of June 2019.

  • 7 December 2018

    A service issue about a temporary increase in Annual Investment Allowance has been added.

  • 16 November 2018

    Downtime previously planned for 17 and 18 November will now take place on 24 and 25 November.

  • 14 November 2018

    Planned downtime for Wednesday 14 November 2018 9:15pm to 2:45am on Thursday 15 November 2018 has been added.

  • 8 November 2018

    Service issue for Thursday 8 November 2018 from 6pm to 11pm has been added.

  • 1 November 2018

    Planned downtime for 3 and 4 November will now take place on 17 and 18 November.

  • 25 October 2018

    Planned downtime for 3 and 4 November added.

  • 22 March 2018

    An Issue about submissions on 19 March 2018 and 20 March 2018 has been added to the page.

  • 19 March 2018

    The service issues section has been updated.

  • 4 January 2018

    A message about some customers experiencing technical difficulties and delayed submission responses has been added to the page.

  • 12 December 2017

    Service availability section updated.

  • 8 December 2017

    The service issues section has been updated.

  • 2 November 2017

    There is a service availability issue causing delayed submission responses.

  • 1 November 2017

    A service issue message about HMRC’s Corporation Tax free filing software has been added.

  • 30 August 2017

    The ‘Changes that may affect your Company Tax Return – Loss reform’ section has been amended with new information about filing your return.

  • 21 July 2017

    The CT600 Return submission problem has been resolved.

  • 18 July 2017

    The service issues section has been updated.

  • 14 July 2017

    CT600 Return submission problem has now been resolved.

  • 13 July 2017

    The service issues section has been updated.

  • 11 July 2017

    The service issues section has been updated.

  • 1 June 2017

    The ‘Service issues’ section has been updated.

  • 17 May 2017

    The ‘Service issues’ section has been updated.

  • 4 May 2017

    The service issues message about the Corporation Tax online return service – returns with an accounting period ending after 31 March 2017 has been updated as the problem is now resolved.

  • 13 April 2017

    New message at ‘Service issues’ added due to online problems with the CATO service.

  • 6 April 2017

    This guidance has been updated to show latest service issues.

  • 9 March 2017

    Information regarding HMRC’s joint filing service and free filing services for Company Tax Returns has been updated.

  • 21 December 2016

    Information regarding HMRC’s free filing service for company tax returns has been updated.

  • 13 October 2016

    The routine renewal of Adobe CT600 Trusted certificate section has been updated to reflect the renewal of the embedded certificate.

  • 31 August 2016

    Spring Budget 2016 content removed

  • 30 August 2016

    Agents unable to log in to their online account issue updated to show the problem has now been resolved.

  • 30 August 2016

    The service issues section has been updated to remove the HM Revenue and Customs online filing software – computations trading losses summary page issue.

  • 24 August 2016

    The ‘Agents unable to log in to their online account’ message has been updated.

  • 11 August 2016

    A service issue message has been added to the page.

  • 7 July 2016

    The Spring Budget 2016: changes that may affect your Company Tax Return section has been updated.

  • 26 April 2016

    ‘Error 9316/9965 using HM Revenue and Customs/Adobe return’ paragraph added to the page under service issues.

  • 21 April 2016

    Removal of ‘Changes that may affect your Company Tax Return’ section.

  • 14 April 2016

    Service issues section has been updated.

  • 12 April 2016

    The service issues section has been updated with information about essential maintenance for Companies House online services.

  • 21 March 2016

    The service issues section has been updated with information from the Spring Budget 2016 about
    changes that may affect your Company Tax Return.

  • 13 January 2016

    Important changes to HMRC’s free filing service for company tax returns

  • 24 December 2015

    Service issues section has been updated.

  • 15 December 2015

    Routine renewal of Adobe CT600 Trusted certificate message added to the page.

  • 24 September 2015

    Planned downtime has been added to this page.

  • 22 September 2015

    Downtime for Corporation Tax online service has been added to this page.

  • 2 September 2015

    Latest updates on creating a new Government Gateway account.

  • 24 August 2015

    First published.