What happens if I miss the self assessment deadline?

Filing your self assessment tax return can be a daunting task, but it’s essential to meet the deadlines set by HMRC. Missing the self-assessment deadline can lead to a range of penalties and additional charges, which can quickly add up if not addressed promptly. In this blog post, we’ll explore what happens if you miss the self-assessment deadline, how to minimise the damage, and how our service can help you avoid these costly mistakes in the future.

8/20/20244 min read

a clock on a wall in a dark room
a clock on a wall in a dark room
The consequences of missing the self assessment deadline

When you miss the self-assessment deadline, HMRC doesn’t waste time in issuing penalties. Here’s a breakdown of what you can expect if you miss the deadline:

1. Immediate £100 penalty

As soon as the clock strikes midnight on 31st January, HMRC will automatically issue a £100 penalty for late submission. This penalty applies even if you don’t owe any tax or are due a refund.

2. Daily penalties

If your tax return is more than three months late, you’ll be charged an additional £10 per day for up to 90 days, which can total up to £900. This is on top of the initial £100 penalty.

3. Six-month penalty

If you still haven’t filed your return after six months, HMRC will impose further penalties. This could be either £300 or 5% of the tax due, whichever is higher. This penalty is in addition to the daily penalties.

4. Twelve-Month Penalty

If your tax return is more than 12 months late, HMRC may impose yet another penalty of £300 or 5% of the tax due, depending on the circumstances. In severe cases where HMRC believes you are deliberately withholding information, the penalty can increase to 100% of the tax due.

5. Late Payment Penalties

In addition to late filing penalties, if you fail to pay the tax you owe by the 31st January deadline, you’ll incur further penalties. These include:

  • 5% of the unpaid tax if it’s 30 days late.

  • An additional 5% if it’s six months late.

  • Another 5% if it’s 12 months late.

6. Interest on late payments

HMRC will also charge interest on any unpaid tax from the day after the payment is due. The interest rate is set by HMRC and can change, so it’s important to settle your bill as soon as possible.

How to minimise the impact of missing the deadline

If you’ve missed the self-assessment deadline, there are steps you can take to minimise the penalties and get back on track:

1. File your return as soon as possible

The sooner you file your tax return, the better. Each day you delay can increase the penalties you face, so make it a priority to submit your return immediately.

2. Pay any tax owed

If you owe tax, pay it as soon as possible to avoid further penalties and interest. Even if you can’t afford to pay the full amount, paying what you can and contacting HMRC to arrange a payment plan can help reduce additional charges.

3. Appeal the penalty

If you have a reasonable excuse for missing the deadline—such as a serious illness, bereavement, or technical issues—you may be able to appeal the penalty. HMRC considers appeals on a case-by-case basis, so be prepared to provide evidence to support your claim.

4. Seek professional help

If you’re unsure how to proceed or need help navigating the appeals process, it’s wise to seek professional advice. This can help you avoid further penalties and ensure you’re on the right track going forward.

How to avoid missing the deadline in the future

Missing the self-assessment deadline can be stressful and expensive, but it’s avoidable with the right planning and tools. Here’s how you can ensure you don’t miss the deadline again:

1. Register for self assessment early

If you’re new to self-assessment, make sure you register with HMRC well in advance of the deadline. The registration process can take up to 10 working days, so don’t leave it until the last minute.

2. Keep accurate records

Throughout the year, keep detailed records of your income and expenses. This will make it easier to complete your tax return and reduce the risk of errors that could lead to delays.

3. Set reminders

Use calendar reminders or apps to notify you of important dates, such as the self-assessment deadline and payment deadlines. Setting multiple reminders leading up to the deadline can help keep you on track.

4. Use our personalised self assessment guide

At The Self Assessment Helper, we offer a simple solution to help you avoid missing deadlines and incurring penalties. For just £9.99, you can access our personalised, step-by-step guide tailored to your unique tax situation. By answering a few questions, you’ll receive a clear, concise guide that walks you through the self-assessment process, ensuring you meet all deadlines and avoid costly mistakes.

5. File early

Don’t wait until the last minute to file your tax return. Aim to complete and submit your return well before the deadline. This gives you plenty of time to address any issues that arise and ensures you avoid the stress of a last-minute rush.

Why choose our service?
  • Tailored to your needs: Our guide is customised based on your specific circumstances, ensuring you receive relevant advice.

  • User-friendly: We break down complex tax rules into easy-to-understand steps, making the filing process stress-free.

  • Affordable: At just £9.99, our service offers exceptional value for money.

Missing the self assessment deadline can result in significant penalties, but with prompt action and careful planning, you can minimise the impact. Understanding what happens if you miss the deadline is crucial to managing the situation effectively. For future peace of mind, consider using our personalised guide to ensure you never miss a deadline again.

Don’t let a missed deadline cause unnecessary stress and financial strain. Contact us today to get started with your personalised self-assessment guide and file with confidence.