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Can I file my own Corporation Tax Return?

At the end of each accounting year/period, limited companies must make a Corporation Tax CT600 return to HMRC along with Company annual accounts

Can I file my own Corporation Tax Return?




Whether you are coming to the end of your Company's first year of trading, or have been trading for several years,at the end of each year you need to file your Corporation Tax return with HMRC and pay any Corporation Tax due. This process includes completing a CT600 (the Corporation Tax return) and attaching a set of IXBRL Tagged Company Accounts. You may choose to do this yourself or use the services of an accountant who has access to IXBRL Tagging software.
In this article however we show you how to do it yourself (yes you can), which will save you money along with having greater control on what you report in your return and accounts.

What you need to know

Once your accounting period has finished, you have a year to file your Corporation Tax Return to HMRC. However, if you are due to pay Corporation Tax, it must be paid to HMRC within 9 months and a day of your accounting period ending. You also need to file your accounts with Companies House within 9 months of the Companies year end.

Ok, so that may sound a bit daunting and official, so lets break it down into simple steps that Easy Digital Filing enables for the create and file a CT600 Corporation Tax return along wth IXBRL Company Accounts.

How do you file to HMRC?

Generally an annual return to HMRC is made up of 3 parts:

  • A CT600 - this used to be a paper form that was posted to HMRC. Now each company must file the information contained in a CT600 electronically. See 'what is a CT600 return' for more information.
  • Computations - these show how your figures in the CT600 are calculated and we take the information you input into your CT600 to create and IXBRL tag your computations.
  • Company Accounts - these are just a standard set of accounts, with a Profit and Loss Statement and the Balance Sheet. The accounting standards applied depend on whether your company is a micro or small entity. These are also tagged with IXBRL, our article 'How to create Micro IXBRL Limited Company Accounts' explains in more depth how to create these.


To file a Corporation Tax return using Easy Digital Filing you will need your Unique Tax Reference - UTR and your HMRC Gateway login details. If you have not already registered with HMRC please see their website. If you are VAT registered or registered for PAYE you will be able to use these login details. You must also ensure that you have activated the Corporation Tax Service on your Gateway Account.

How does Easy Digital Filing file to HMRC?

We have produced easy to follow templates: one that allows you to create the CT600 and the associated computations, and one that creates the tagged accounts.
The CT600 asks you to fill in your income information in a way that allows us to create the computations in the background. There are additional pages if you need to report on items such as Capital Allowances, how to file a Research and Development claim, additional income, and loans to participants.

The accounts similarly have simple to use templates. For Micro Companies there are just four templates you need to fill in. Once you have filled in your details we format the accounts with iXBRL tags, ready for submission to HMRC.

We appreciate that creating your tax return can take time, especially when juggling the commitments of running your company as well, so you can log on and off as many times as it takes to complete your return, even over months! Your data is continually saved across multiple UK located servers, so you have no worries on ever losing data unless you want to (when you delete a filing all data is removed after 48hours, so we can recover it up to then - just chat a request for reinstatement).

Once you are happy that you have entered in all your data, and are ready to file to HMRC, we ask you to pay at this point - so no need to commit before you have tested our software up to the point of filing. We offer email, an online chat, knowledge based articles, item context tooltips, Inline Help pages, and of course phone support to help you along.

When you are ready to submit to HMRC and/or Companies House, you just click the submission button and the platform does the rest; the accounts and computations are IXBRL Tagged, encoded and attached to the Digital CT600 and transmitted through to the HMRC Gateway. You will receive instant feedback as to whether your filing was successful, if you have made an error, you can correct it and resubmit (as many times as you need to), that's all included in the price you pay.

Please visit our Tax Filing Knowledge Base if you require any further guidance or contact us.

We now also offer the ability to file to Companies House at the same time as you file to HMRC. Please see our article on Filing Company Accounts to Companies House. Remember Companies House require you to file your accounts to them within 9 months of end of your accounting period (and the fine is slightly more than HMRC).



This article is information only and has been prepared for general guidance on matters of interest only, and does not constitute legal, accounting, tax, investment or other professional advice or services. You should not act upon the information contained in this article without obtaining specific professional or legal advice. No representation or warranty (express or implied) is given as to the accuracy or completeness of the information contained in this article, and, to the extent permitted by law, Comdal Limited, its members, employees and agents do not accept or assume any liability, responsibility or duty of care for any consequences of you or anyone else acting, or refraining to act, in reliance on the information contained in this publication or for any decision based on it.