# Personal Income Tax Return (Form IT1)

Country: Isle of Man
When: 6 October following the end of the tax year (6 April to 5 April). Example: for the 2025/26 tax year (ending 5 April 2026), the return is due by 6 October 2026.

Annual Isle of Man income tax self-assessment return for resident individuals with income from employment, self-employment, property, investments or other sources. Filed with the Assessor of Income Tax. The return covers the tax year 6 April to 5 April, with a deadline of 6 October (6 months after year-end).

## Who this applies to

- Isle of Man residents with self-employment income
- Company directors with income not fully taxed under ITIP
- Individuals with Isle of Man rental or property income
- Individuals with investment or overseas income
- Anyone issued with a notice to file a return by the Assessor

## What to file

Form IT1 (Individual Income Tax Return) detailing all sources of income including employment (ITIP summaries), self-employment (accounts or computation), rental income, and investment income. Claim personal allowances, reliefs and losses.

## How to file

Online via myGov.im (preferred) or by paper return to the Assessor of Income Tax. Online filing is encouraged and gives instant confirmation of receipt.

## Payment due

Any balance of tax due after ITIP deductions is payable by the same 6 October deadline. If a payment on account was required (for significant non-ITIP income), an earlier instalment may have been due.

## What happens if you miss it

Fixed penalty of £250 for filing after the 6 October deadline. Additional penalties for tax-related inaccuracies and late payment interest. The Assessor can make a determination if no return is filed and charge tax based on that determination.

## Submission checklist

- Gather ITIP P60 or equivalent for employed income
- Prepare self-employment accounts and profit computation
- List all rental income and allowable expenses
- Include dividends and investment income
- Claim all eligible personal allowances (£14,500 for 2025/26)
- Calculate and pay any balance of tax due by 6 October
- Keep evidence of all figures for at least 5 years

## Common mistakes to avoid

- Missing the 6 October deadline: many individuals confuse it with the UK's 31 January SA deadline, which does not apply in the Isle of Man
- Forgetting to include dividend income from Isle of Man or overseas companies
- Not claiming all eligible personal allowances and reliefs
- Directors failing to include all benefits in kind received from their company

Source: https://www.gov.im/categories/tax-vat-and-your-money/income-tax-and-national-insurance/