Release notes for legacy desktop version

UK - April 2025 (partnership)

ONESOURCE Corporate Tax v17.0

Release summary

HMRC have released updated versions of the following forms supporting online submissions:
  • SA800 (2025)
  • SA801 (2025)
  • SA802 (2025)
  • SA803 (2025)
  • SA804 (2025)
We have made changes to the FY 2025 computation template packs and files to support the new forms.
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.
A full list of the updated computation template packs included in this update can be found at Computation template packs released.

ONESOURCE Corporate Tax - Next Generation

Our Next Generation tax software for Partnerships is available and delivers significant benefits to users preparing Partnership tax returns including:
  • Fully web-based solution ensures you are always using the most up to date version
  • Support for all bases of preparation in a single calculation
  • Flexible, modular approach to building the computation to ensure you only complete sections you need to
  • Extensive support for import and automatic population of the tax return
  • Reporting functionality to enable you to extract relevant data for analysis and dashboards
  • Integration with the ONESOURCE platform
This will be the final content release on the legacy desktop platform. Returns for periods after 2024/2025 must be completed on our new Next Generation platform. To discuss moving to this platform please contact your account manager.

Updates - Partnership and SA800 forms

Area of change
Details and limitations
Support for the new SA800, SA801, SA802, SA803, and SA804 (2025)
ONESOURCE has been updated to include the 2024/25 partnership tax return forms and associated e-filing rules and validations.
For further guidance, please refer to the updated SA800, SA801, SA802, SA803, and SA804 guides included in this release.
Annual turnover threshold change
The lower threshold that determines in which boxes you are required to give details of income and total expenses and work out the partnership’s taxable profit has changed from £85,000 to £90,000. If your annual turnover was less than £90,000 (or would have been if you had traded for a whole year), fill in boxes 3.24 to 3.26, and if it was between £90,000 and £15 million, fill boxes 3.27 to 3.73.
Box 3.9 - Traditional accounting instead of cash basis
HMRC have updated the description of box 3.9 to reflect whether you used traditional accounting instead of cash basis accounting. It now asks if you have traditional accounting whereas previously it asked if you used “cash basis”. We have updated the question in Partnership-wide figures and reliefs [O] sheet to reflect the change accordingly.
For further guidance, please refer to the updated SA800 guide included in this release.
Early Build disabled for following financial years
The “Build new period” functionality has been disabled. Now, if you try to create an “Early Build” calculation for a period that would end after 5th April 2025, you will receive an error message advising you to switch to ONESOURCE Corporate Tax Next Generation version.

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 on the evening of Friday 11th April. 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, 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. More information about our new status page is available here.
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 Friday 11th April.
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 Friday 11th April.
To be able 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, contact our support team.

Computation pack - Computations, claims, and forms supported

Partnership
Computation templates for the Tax Year 2024/25:
  • UK Partnerships
  • UK Partnerships – Multiple bases
Supporting, where relevant, the following return form and supplementary pages:
  • SA800
  • SA801
  • SA802
  • SA803
  • SA804

This article applies to:

  • PRODUCT: ONESOURCE Corporate Tax

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