Do I need to attach accounts to my CT600?

In most cases you do need to attach accounts to your CT600. For exceptions, see below.

You can attach accounts in two formats:

• iXBRL – for most companies
• PDF – usually for charities only.

Attaching iXBRL accounts

iXBRL accounts need to be in .html or .xhtml. 

Support can supply you with a list of companies that will undertake iXBRL conversions from Excel

To attach iXBRL accounts, follow these steps: 

1. Open the CT600.
2. Go to Accounts and Computations.
3. Under I am attaching Accounts... select Relating to this period or Relating to a different period as applicable. 
4. Go to Attachment Management.
5. Set Computations and Accounts to iXBRL.
6. Click on Add Accounts.
7. Click on one of the following:
   • Attach from Accounts Production – select the relevant accounting period and click on Attach.
   • Attach from External Source – browse to your accounts file and click on Open.
8. Check the table for Documents currently attached to this return: to make sure that your computations and accounts are attached as required.

Attaching PDF accounts

To attach PDF accounts, follow these steps:

1. Open the CT600.
2. Go to Accounts and Computations.
3. Untick all boxes.
4. Select Other - PDF attached with explanation from the drop-down menu.
5. Go to Attachment Management.
6. Set Computations to iXBRL.
7. Click on Add Other PDF.
8. Click on OK.
9. Browse to your PDF accounts and click on Open.
10. Check the table for Documents currently attached to this return: to make sure that your computations and accounts are attached as required.

Exceptions

You don't need to attach accounts in the following situations:

• The accounts cover a long period. 
• The company is in liquidation.
• The company is dormant.
• You're filing an amendment to accounts already submitted.

For further information, read HMRC's guidance on Company Tax Returns: format for accounts forming part of an online return.

To file a CT600 without adding accounts, follow these steps:

1. Open the CT600.
2. Go to Accounts and Computations.
3. Untick all boxes.
4. Select the applicable option from the drop-down menu.
5. Go to Attachment Management.
6. Check the table for Documents currently attached to this return: to make sure that only the computations are attached.