With the end of summer behind us, it’s time for self-assessment taxpayers to pay attention to a couple of key dates this month to avoid penalties. MoneyWeek are reminding us of the deadlines, here is a summary and what they mean for you:

October 5th: Deadline to Register

• If you are newly self-employed, a sole trader, or a new landlord, you must register for self-assessment with HMRC by this date for the 2024/2025 tax year.
• This also applies to anyone who has earned more than £1,000 in untaxed income, including from a side-hustle or from providing services online.
• Failing to register on time could result in penalties, including a fine of up to 100% of the tax owed if HMRC believes you are deliberately concealing income.

October 31st: Deadline for Paper Returns

• For those who choose to file their tax return on paper, the deadline to submit it is October 31st, 2025.
• The deadline for online tax returns is later, on January 31st, 2026.
• An initial penalty of £100 will be issued for late paper submissions, followed by additional daily and percentage penalties.

Expert Advice Financial experts cited in the article suggest that filing and paying early can help ensure that your payments are accurate and you don’t get caught by high interest rates for underpaying.