If you wish to file an amended return, you will need to ensure that the amendment box within the filing template has been switched to 'YES' before proceeding. This is a required step - without toggling this option, your submission will be treated as an original return rather than an amendment, which could result in duplicate or incorrect filings.

It is also important to be aware that both HMRC and Companies House have specific rules and deadlines governing when amendments can be made:

• HMRC allows amendments to a Corporation Tax return up to 12 months after the original filing deadline. After this point, you would need to contact HMRC directly to request any corrections.
• Companies House also permits amended filings, however these must be submitted in the correct format and within the appropriate timeframe to be accepted.