When you log in to MyTax, your tax-related letters will change from paper to electronic form automatically. Read more about the changes.
Use this form to file a business tax return for
- limited-liability company and cooperative
- non-mutual housing company
- co-operative bank and savings bank
- mutual insurance company and insurance association
- pension trust
- tax resident foreign organisation.
Foreign corporate entities and branches file form 6U.
Choose how to submit
Submit the tax return and the required financial statements electronically in MyTax.
You can also give the information electronically by uploading a file in the Ilmoitin.fi service.
If you use Ilmoitin.fi, send us the attachment forms together with the main tax return form.
Do not send any paper forms if you use an online channel for filing the company’s tax return.
Guidance for income tax returns as software files — specifications of data formats
You can file on paper only if there is a special reason (for example, if electronic filing is impossible due to technical difficulties). If you file on paper, you need not apply for a special permission, and the Tax Administration does not need to be notified of the reason in advance. The Tax Administration may ask for the reason in connection with tax control.
You can find the return address on the first page of the form.
Please notice when filling out the tax return
- If you opt for sending the tax return by post, we recommend that you fill out the form on your computer before printing it out. It is important that you fill in the details clearly, because they are read by machine.
- If you file the tax return on paper, the details on financial statements which are transmitted to the Trade Register must be stapled together with Form 63 as the cover page.
- Whenever a corporate taxpayer has assets to report – even during the accounting periods when you booked no depreciation expenses or made no reserves – Form 62 is a mandatory enclosure. Complete any other enclosure forms if necessary.
Download the form
Instructions
Attachment forms
- 7A, Profit-and-loss acc. for Personal Source of Income
- 62, Itemization of reserves, revaluations and depreciation
- 63, Financial Statements for the Tax Administration and the Trade Register office
- 67A Claim for additional deduction for research and development – sub-contracting invoices
- 67Y Claim for general additional deduction for research and development (2023 general additional deduction and 2024 combined deduction)
- 78, Explanation of transfer prices
- 82 Account of cross-border hybrid arrangements
- 83 Account of exit tax
Forms for previous years
Huomio osio alkaa
The online authorisation mandate
You can use the Suomi.fi Authorization to enable you to deal with taxes for another person – including legal persons, companies, other entities – through e-services, over the telephone, or by visiting a service point on their behalf.
Huomio osio päättyy
Huomio osio alkaa
Letters of authorisation on paper
You can receive a letter of authorisation written in the name of a company, to manage a single tax-related issue. If you – either personally or for an organisation that had been authorised – submit tax-related information on paper, a copy of the letter of authorisation has to be enclosed. A letter of authorisation does not provide access to MyTax.
Power of attorney for managing the taxes of a company (3804)
Huomio osio päättyy
Key terms:
The Tax Administration can use automated decision-making in the context of resolving tax matters. This means that a decision concerning your tax matter may be based on partial or full use of an automated decision-making system. Read more about automated decision-making at the Tax Administration (only in finnish).
Page last updated 6/10/2026