If company accounts have been prepared in third-party software such as VT Final Accounts, IRIS, or Sage Accounts Production, you can attach the iXBRL file to a BrightTax Corporation Tax return for submission to HMRC. BrightTax will attempt to import key figures from the iXBRL file into the CT computation automatically.

• You must have the iXBRL accounts file ready — this should be produced by your accounts software and saved to your computer.
• The CT return must be open in BrightTax before you can attach the file.

1. Open the CT return in BrightTax.
2. Expand the CT navigation toolbar using the toggle switch at the top left.
3. Click the Swap Mode button. This switches the CT mode to enable the Attach Accounts feature.
4. Click the Attach Accounts button that appears after swapping mode.
5. In the pop-up window, click the Add button.
6. Browse your computer and select the iXBRL file. You can attach both Full Accounts and Filleted Accounts if required.
7. Click OK to attach the file.
8. BrightTax will process the file and attempt to import figures into the CT computation — including turnover, profit/loss, and depreciation.

Once the iXBRL file is attached, review the CT computation to confirm the imported figures are correct. In particular, check:

• Net profit or loss per accounts
• Depreciation figure
• Turnover

Correct any figures that have not imported accurately by switching to Edit mode and typing directly into the relevant fields on the CT computation page.

Q: What file format does the iXBRL file need to be in?

A: iXBRL files are typically in .html or .xml format. BrightTax accepts standard iXBRL files produced by compliant accounts production software.

Q: Can I attach both full and filleted accounts?

A: Yes. Where both versions are required — for example, full accounts for HMRC and filleted accounts for Companies House — you can attach both in the same CT return.

Q: What happens if the iXBRL file contains an error?

A: BrightTax will flag any errors found during the file processing. Review the error message and correct the iXBRL file in your accounts software before re-attaching.