Corporation Tax Online

Welcome to HMRC's Corporation Tax Online services.

Did you know that you can file your Company Tax Return over the Internet?

Corporation Tax (CT) Online services allow most companies and agents on behalf of companies, to file company tax returns over the Internet. A company tax return is made up of a company tax return form (CT600) with accounts and computations and other supporting documentation. Computations, accounts and other supporting documentation must be sent in PDF format. However some third party software products may allow computations to be sent in XBRL format.

Using the service will bring you many benefits.

Some of these are:

  • Speed of communication and processing
  • The software or online forms will calculate your tax liability for you
  • You get an online acknowledgement when your return is received
  • It's secure and more convenient - you can use the service day or night

CT Online also offers the following:

If you are a company you can:

  • View your company's corporation tax position. You can see details of your liabilities and payments for each accounting period as well as any interest or penalties that have been charged.
  • Set up and manage other users and assistants from within your organisation so that they can use the online services you have enrolled for.
  • Add or change telephone, fax, email contact details for registered office and communication addresses.
  • Add or delete communication name and address details (other than registered office details).
  • Add or change agent authorisation.

Unincorporated associations can also change their names and addresses.

If you are a nominated company within a Group Payment Arrangement (GPA) you can:

  • View your companies' corporation tax position. You can see details of your liabilities and payments for each accounting period as well as any interest or penalties that have been charged.
  • View the Group's liabilities and payments made for the last five years of Group Payment Periods (GPP). You can see details of the group payments made for each year and the associated participating companies' tax liabilities.

If you are an agent you can:

  • View your client companies' corporation tax position, including GPA clients where applicable, provided the company has authorised you to act as agent (usually by using form 64-8). You will be able to see details of your client companies' liabilities and payments for each accounting period and any interest or penalties that have been charged.
  • Set up and manage other users and assistants from within your organisation so that they can use the online services you have enrolled for.
  • Add or change telephone, fax, email contact details for the company's registered office or communication addresses.
  • Add or delete communication name and address details for the company (other than the registered office details).
  • Change your own address and contact details.

To register for these services or to visit our Frequently Asked Questions please visit our Online Service web site.

Corporation Tax Online Service Availability

For information on the availability of the online service, please check the Service availability page.

Our Service issues page list any important issues that customers have experienced when using the service and explains how they are being dealt with