Error 3318 appears when you submit pre‑FRS 102 accounts to HMRC and the reporting period doesn’t match the referenced Accounts Taxonomy. Date mismatches, outdated versions, or old masters usually cause this.

To resolve this error, check the following:

Period start and end dates

1. Open Sage Accounts Production, select Database.
2. Select Reporting options, go to the Dates tab.
3. Review the period commencement and period end dates.

Your version number

If you're using an older version of Sage Accounts Production, update it to the latest version.

Update to the latest master

If the client is on an older master, update to the latest master, re-produce the iXBRL file, attach it to Corporation tax, and resubmit.

Next Steps

Once you update, you need to recreate the IXBRL accounts and choose to overwrite and create new. You’ll then attach the new file when submitting to HMRC. 

If the error persists

If you're using the latest master and the error persists, contact us and we can check the iXBRL files for you.