New version of Ilmoitin.fi has released 3 February 2026

Key changes:

• Ilmoitin.fi accepts income tax returns for corporate taxpayers´ 2025 accounting periods. Users can both check and submit returns (Forms 4, 6, 6B, 6C and 6U).
  • In addition to the annual changes, there have been other changes to the following data format specifications: 4, 6, 6B, 62, 71A, 71B, 8A.
  • Data file specifications — income tax returns
• Rental income - farmlands, woodlands, forest and other rental property (7L).
  • You can check and submit self-employed businesses´ income tax returns 7L for tax year 2025.
• Opening the Archive page:
  • When navigating to the page, the sending information of files sent via the ApitamoPKI interface is not retrieved.
  • The metadata of files sent via the ApitamoPKI interface can be viewed by searching for the customer ID.
  • This only applies to companies to which files are sent via both the www.Ilmoitin.fi service and the ApitamoPKI interface.
• The data format specifications for annual information returns for the 2026 reporting year are published on 3 February, but their formats will not be available until the March version of Ilmoitin.fi is launched on 24 March 2026. 
  • Data file specifications - Annual information returns & Instructions
• Application for refund of tax withheld and application for tax-at-source cards (WHT ja TAS).
  • Fixed MessageRefId check and spaces are no longer allowed.
  • Removed OBAN bank account check.
• FATCA annual return has been removed from comments if the Individual/TIN is 000000000 or AAAAAAAAA and the IssuedBy attribute is not provided or its value is US.
• Test environment testi.ilmoitin.fi
  • Submitted files will be cleaned up once a day in the future, so old files will open empty in the Archive. This change will be implemented in the coming months.

Software developers – events  

“Clinics” on Teams (held on Teams, the language is Finnish)

Our “clinic” style events will offer IT developers a wide variety of information updates. If you have questions or suggestions for issues to be discussed at the next “clinic”, you are welcome to send e-mail to ohjelmistotalot(at)vero.fi – for subject, write: Klinikka. 

For 2026, there is an updated schedule for upcoming events on Teams, which you can find on the page Tilaisuudet - vero.fi (in finnish). 

Cooperation Days between the Tax Administration and Software Vendors Online (held in Finnish)

During the events, you will hear up to date presentations on changes in taxation and their impact on software development. If you have topics or questions, you would like us to address, you can send them by email to ohjelmistotalot(at)vero.fi with the subject line “yhteistyöpäivä”.

The cooperation days will be organized twice during 2026

• Spring Cooperation Day: Tuesday, 26 May 2026
• Autumn Cooperation Day: Tuesday, 17 November 2026

The detailed schedule and registration will be published later on the page Tilaisuudet - vero.fi (in finnish).

Information on deadlines and updates 

• e-Filing of tax returns and information returns, schedules for 2026 (in Finnish)
• Schedule of updates to the Tax Administration’s file check module (in Finnish)
• Planned downtime 

How to contact us or make enquiries 

ohjelmistotalot(at)vero.fi 
 
You can use this e-mail address of the Tax Administration (for software houses) to ask questions related to the Incomes Register as well. We will forward the questions to the Incomes Register Unit. However, we remind all users that our e-mail is: 

• Intended for those who work with IT development at commercial software vendor companies;
• Designed to give guidance and support to IT development; and
• Not designed for any error processing. Instead, if you notice an error or if you become aware of a technical problem, always use the Observation form to inform the Incomes Register of it.