Completing your own tax return might seem like a good way to save money. With online tools and guidance available, many people in the UK are tempted to handle their Self Assessment themselves. However, what looks simple on the surface can quickly become complicated—especially if your income isn’t straightforward.
Mistakes, missed deadlines, or incorrect claims can lead to penalties from HM Revenue and Customs (HMRC), and in some cases, cost far more than hiring a professional in the first place.
In this guide, we’ll explore whether doing your own tax return is worth the risk—and why using a competent accountant is often the safer option.
Why People Choose to Do Their Own Tax Return
Many people decide to complete their own tax return for one main reason: cost.
Hiring an accountant involves a fee, while submitting your own return online through HM Revenue and Customs is free.
For those with very simple finances—such as a single source of income—this can seem like a straightforward choice.
There’s also a growing belief that software or AI tools can replace professional advice. While these tools can be helpful, they don’t replace tailored guidance or accountability.
The Hidden Risks of Doing It Yourself
While filing your own tax return is possible, there are several risks that are often underestimated.
1. You Might Misreport Your Income
One of the most common issues is incorrectly declaring income.
This can happen if you:
- Forget additional income streams
- Misunderstand what needs to be reported
- Overlook small but taxable amounts
Even minor errors can trigger questions or penalties from HMRC.
2. You Could Miss Allowable Expenses
Many people who file their own returns fail to claim everything they’re entitled to.
For example, self-employed individuals often miss:
- Business expenses
- Home office costs
- Mileage or travel claims
This means you could end up paying more tax than necessary—effectively costing yourself money.
3. Tax Rules Are More Complex Than They Appear
UK tax rules can change frequently, and what applied last year may not apply now.
Areas that often cause confusion include:
- Dividend allowances
- Property income rules
- Pension tax relief
Without up-to-date knowledge, it’s easy to make mistakes that go unnoticed until later.
4. You’re Fully Responsible for Any Errors
When you submit your own tax return, you take full responsibility for its accuracy.
If something is incorrect, HM Revenue and Customs will hold you accountable—not the software or tool you used.
This can result in:
- Financial penalties
- Interest on unpaid tax
- Potential investigations in more serious cases
5. It Can Take More Time Than Expected
What seems like a quick task can turn into hours of research and admin.
You may need to:
- Gather records
- Understand tax rules
- Double-check calculations
For many people, the time spent can outweigh the cost of hiring an accountant.
The Advantages of Using a Competent Accountant
For most people, using a qualified accountant offers significant benefits.
Accuracy and Compliance
An experienced accountant understands the latest tax rules and ensures your return is accurate and compliant.
This reduces the risk of:
- Errors
- Penalties
- HMRC enquiries
Maximising Tax Efficiency
A good accountant doesn’t just file your return—they help you pay the correct amount of tax, and not more than necessary.
They can identify:
- Allowable expenses
- Tax reliefs
- Planning opportunities
This often saves more money than their fee.
Peace of Mind
Knowing your tax return has been handled professionally removes a lot of stress.
If HMRC has questions, your accountant can:
- Respond on your behalf
- Provide explanations
- Help resolve issues quickly
Support as Your Finances Grow
As your income becomes more complex—through self-employment, property, or investments—having professional support becomes increasingly valuable.
An accountant can guide you through:
- Changing tax obligations
- Business growth
- Long-term planning
When Doing It Yourself Might Be Acceptable
There are situations where completing your own tax return may be reasonable.
For example:
- You have a single, simple income source
- No additional earnings or reliefs to claim
- You fully understand HMRC requirements
Even in these cases, it’s important to be confident in what you’re doing.
Why AI and Software Aren’t a Complete Solution
While technology can assist with tax returns, it has limitations.
AI tools and software:
- Rely on the information you provide
- Don’t fully understand your personal circumstances
- Can’t take responsibility for errors
They may help with basic tasks, but they don’t replace professional judgement or accountability.
The Real Cost of Getting It Wrong
Trying to save money by doing your own tax return can backfire if mistakes are made.
Potential costs include:
- HMRC penalties
- Overpaid tax from missed claims
- Time spent fixing errors
In many cases, these costs exceed what you would have paid for professional help.
Final Thoughts
Completing your own tax return might seem like a simple way to save money, but it comes with risks that are often overlooked.
For straightforward situations, it may be manageable. However, as soon as your finances become more complex, the chances of errors—and the cost of those errors—increase.
Using a competent accountant not only reduces risk but can also save you money and time in the long run. For many people, it’s not just about convenience—it’s about getting it right.