When submitting a CT600 to HMRC you may encounter the following submission error message:

This occurs when the iXBRL tagging applied to the accounts does not meet the expected standard.

If you are using TaxCalc, please ensure you are running the latest version of the application. For more information on how to do this, please review How do I check if my TaxCalc is up to date?) Once you have successfully updated TaxCalc, you will need to remove and re-attach the accounts before re-attempting online submission. 

If you are using a third party service provider for your accounts production, you would need to contact them directly to see if they have a setting or software update available to provide the most recent iXBRL tagging regime provided by HMRC. Once you have successfully updated the tagged accounts, you will need to remove and re-attach the accounts before re-attempting online submission.