Release notes for legacy desktop version

UK - May 2025

ONESOURCE Corporate Tax v17.0

Release summary

We provide specific updates for items identified in the ONESOURCE Corporate Tax legacy - Partnership module since the 2024/25 SA800 update in April, more details are given in the following. Additionally, we update the latest HMRC interest rates on underpaid and overpaid tax.
Be aware that this year will be the final year that we will be releasing new and updated template packs for the legacy ONESOURCE Corporate Tax software. Version 18.0 is due for release in July 2025, and will support accounting periods ending up to 31 March 2026. Accounting periods ending after that date will be supported on the web-based ONESOURCE Corporate Tax software.
These notes are structured to focus on the key functional areas of change, rather than specifying the changes made to each of the individual modules. Unless otherwise stated, changes have been made to all computation types.
A full list of the updated computation template packs included in this update can be found in the following Computation template packs released section.

Updates - SA800 forms

Area of change
Details and limitations
Spurious text printing beneath address on full partnership statement
We removed text that was incorrectly appearing beneath the address on the full partnership statement, which was inadvertently added following changes made in April to support the new graphic design of the SA800 return forms. Where the full partnership statement has already been developed, it should be erased and re-developed to get the latest version.
Figures in boxes 7.7 to 7.18 on the SA804 misaligned
We re-aligned boxes 7.7 to 7.18 on the SA804, after it was identified these were no longer positioned correctly. Again, this arose following this year's graphic design changes to the return forms. Where the SA804 form has already been developed, they should be erased and re-developed to get the latest version.
Cannot see if CT or IT version of the partnership statement on-screen
We adjusted the colour of the version indicator on the partnership statement pages to ensure that it is now visible on-screen as well as on the printed version of the statement. Where the full partnership statement has already been developed, it can be erased and re-developed to get the latest version.

Updates - HMRC interest rates

Area of change
Details and limitations
Rates of interest on underpaid and overpaid tax
We updated the four CTSA interest rates used within the software. The updated rates cover interest:
  • charged on underpayments of QIPs
  • paid on overpayments of QIPs
  • charged on late payments of Corporation Tax
  • paid on repayments of Corporation Tax.
The rates are defined on the HMRC interest rates for late and early payments website. You can check current and historical rates in ONESOURCE by selecting
Data
 then
CTSA interest rates
.
These rates are used in the
Tax payments and interest sheet
, and interest on outstanding tax balances or overpaid amounts is automatically calculated.
Interest rate calculations have a footnote, indicated by “§”, which explains the interest calculation. The footnote appears at the end of the page when printed or reviewed, and can be viewed in the end and side of the screen.
Updates with revised interest rates are issued as needed.

Release development

Hosted customers
The update for ONESOURCE Corporate Tax v17.0 will be deployed by Thomson Reuters as part of our hosting services for ONESOURCE Corporate Tax users by the evening of Friday 23rd May. We will minimise the downtime required for this update.
For further details relating to the scheduled maintenance, including the start time and end time of the maintenance, click here to access our system status page. ONESOURCE Corporate Tax is currently identified as Corporate Tax (legacy) [EMEA] and can be found under our “Direct Tax” applications.
If you would like to receive emails to notify of updates to our status page, you can subscribe through our status page. We recommend you use a modern browser such as Chrome, Firefox, or Edge to set your subscription preferences. View the status page for more information.
Self-hosted enterprise customers
The update for ONESOURCE Corporate Tax v17.0 will be made available by Thomson Reuters via a secure download site during the week ending Tuesday 27th May. Installation instructions along with other relevant documentation will be included in the download file.
Non-hosted customers
The update for ONESOURCE Corporate Tax v17.0 will be made available on Tuesday 27th May.
To apply the update, you will need to have installed ONESOURCE Corporate Tax v17.0. If you have not yet installed v17.0, you can download the setup files from the Thomson Reuters download site. Installation instructions along with other relevant documentation will be included in the download file.
Once you have v17.0 installed, access the application, and select the
Check for updates
 option from the “Help” menu. This will initiate the download of the relevant files. You should then close and restart the application and the updates will be applied.
If you are unable to install the updates via the OCT application, please contact our support team.

Computation template packs released

Computation pack: Partnership
Computations, claims, and forms supported:
Updated versions of the computation template packs for the 2024/25 tax year supporting the following return forms:
  • SA800 (2025)
  • SA801 (2025)
  • SA802 (2025)
  • SA803 (2025)
  • SA804 (2025)

This article applies to:

  • PRODUCT: ONESOURCE Corporate Tax

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