Symptoms:

When submitting CT600 return with attachments of Accounts and Computations in iXBRL format for an accounting period on or after 1st January 2016, HMRC servers may reject the submission with a HMRC validation:

Error 3318: The period to which this Return's Accounts applies does not coincide with the effective from/to dates of the referenced Accounts Taxonomy. Please correct and re-submit.

Cause:

HMRC updated their servers with a new Accounts Financial Reporting Standard (FRS) Taxonomy during October 2016. This meant accounts for accounting period starting on or after 01/01/2016 are being rejected with HMRC validation Error 3318. There is no backward compatibility built into the new FRS Taxonomy.

Solution:

Where you are receiving this error and have attached Accounts iXBRL file created through a third party Final Accounts Production software or have had your accounts tagged, please contact your software provider to for updates they may have for the new accounts taxonomy.

Solution below is only applicable if you are using the free in-built accounts iXBRL template within Andica CT600 software.

Version affected: Andica CT600 Version 2016.0.0 or older.

We have updated version 2016 software to handle the FRS Accounts Taxonomy using a cut-down version of FRS 102. Email us for an update if this issue affects you and your annual licence has not expired.

Please note, for the new taxonomy to be applied to your returns for accounting period starting on or after 01/01/2016, you will need to delete that accounting period and re-enter all data. Ensure you have taken a full backup of the data files, details are provided in 'Backup and Restore' section of the user guide.