IRIS Important Known Issues

It is important to us that we resolve any problems that are found in the IRIS Accountancy Suite.

If your problem is listed below, we are working hard to resolve these as quickly as possible.
Issues that have been fixed or are due to be fixed in the next release, are identified as such.
For information on the next release dates, click here.

Issues resolved in the Spring 2026 service pack release v26.1.10.60

IRIS Personal Tax

Close Company Dividend Field Rejects Zero Value, Causing EMP7.3 Validation Error
The ‘Dividends that you received from this Close Company’ field in the Employment – Earnings screen was not accepting a value of £0.00, preventing box 7.3 from being populated and triggering an incorrect validation error “Close Company [EMP7.3] must be present if [SA102:Was this company a close company] equals ‘yes’”. 

IRIS Business tax

CT600 – Box 650 not completed for RDEC claims
When filing a CT600 for a small or medium-sized company with an RDEC claim, Box 650 was not being automatically populated. If Box 657 had been completed, this triggered an online filing error.

Outstanding issues

IRIS Business Tax

CT600 – HMRC validation error for Loans to Participators (Box A20/A45)
At Budget 2025, the rate of tax payable under the loans to participators regime increased from 33.75% to 35.75%. This new rate applies to loans made or benefits conferred on or after 6th April 2026, and the product has been updated to reflect this change.
However, HMRC’s Corporation Tax online service will not be updated to support the new rate until 6th April 2027.
Workaround
If the new rate applies to your company and you need to file your Corporation Tax return before 6th April 2027, HMRC has advised that you will need to amend your return after 6th April 2027 to reflect the correct rate. Please contact HMRC for guidance on how to proceed. We have also contacted HMRC to seek further clarification and will provide an update when additional guidance is available.

Multiple Trade Losses Brought Forward for Extended Period Incorrect 
Where a business has multiple trades and has an extended accounting period, the losses brought forward are incorrect for the 2nd CTAP.
Workaround 
There is no workaround for this issue.
This issue is due to be resolved in the Summer 2026 release.