The issue 

HMRC has identified a number of cases where the following boxes on the CT600 may incorrectly include brought-forward losses: 

• 805 and/or 810: UK property business losses;
• 830 and/or 835: non-trading losses on intangible fixed assets; and
• 850 and/or 855: management expenses.  

HMRC first contacted taxpayers about this in November 2022. Since then, HMRC has worked with software developers to address the errors. ICAEW understands that fewer companies are now affected as a result.   

Action required 

HMRC will use the figures shown in the tax computations, not the CT600, as the accurate loss amounts for the company.  

If the company believes that the CT600 figures are correct, it should email HMRC using the contact details provided within 60 days of the date of the letter. In the email, the company should explain why it thinks the CT600 entries are correct.  

No action is required if the company agrees with HMRC. 

The letter suggests that the company may wish to discuss the issue with its agent if it has one.  

Future submissions 

It is possible that software developers may not have updated their products before the next CT600 is due to be submitted. In this case, the company should overwrite the entries to ensure that the boxes above do not include brought-forward losses. If this is not possible, the company should include a free format note in the tax computations.  

Further information 

• Template letter provided by HMRC