For many individuals in the UK, completing a Self-Assessment tax return is a necessary part of managing personal finances. Whether you receive income from employment, property, self-employment, dividends or overseas sources, ensuring your return is accurate and submitted on time is essential.
Who Needs to File a Self-Assessment?
Not everyone in the UK needs to file a Self-Assessment tax return. However, you must complete one if you:
- Are self-employed or a sole trader
- Earn more than £1,000 from self-employment
- Receive rental income from UK or overseas property
- Earn dividends or investment income
- Have income from overseas
- Are a company director
- Receive untaxed income
- Have capital gains to report
- Need to claim certain tax reliefs
If you are unsure whether you need to file, Maratax can review your circumstances and provide clear guidance.
Key HMRC Deadlines
Meeting deadlines is crucial to avoid penalties. The main Self-Assessment dates are:
- 31st October – Deadline for paper returns
- 31st January – Deadline for online returns
- 31st January – Tax payment deadline (balancing payment and first payment on account)
- 31st July – Second payment on account deadline (if applicable)
Missing these deadlines can lead to automatic penalties, regardless of how small the tax bill may be.
Penalties for Missing Deadlines
HMRC penalties can escalate quickly:
- £100 – Immediate fixed penalty for missing the filing deadline
- £10 per day (up to 90 days) – Late filing
- £300 or 5% of tax owed – After six months
- A further £300 or 5% of tax owed – After twelve months
Interest is also charged on late payments.
Working with a Chartered Tax Adviser ensures your return is submitted correctly and on time, significantly reducing the risk of these avoidable costs.
Common Self-Assessment Mistakes
Self-assessment can be complicated, and many individuals struggle with:
- Reporting income inaccurately
- Forgetting to declare rental, overseas or investment income
- Miscalculating expenses
- Overlooking capital gains
- Missing key reliefs and allowances
- Not keeping adequate records
At Maratax, we ensure your return is accurate, complete and fully compliant. We also highlight tax efficiency opportunities you may not be aware of.
Best Practices for a Smooth Self-Assessment
To keep your tax affairs organised and stress-free, consider the following:
- Keep records throughout the year
Maintain receipts, invoices, bank statements and property records.
- Submit your return early
Avoid the January rush and reduce the risk of last-minute errors.
- Understand payments on account
We help clients understand and plan for these instalments to prevent cashflow surprises.
- Seek expert advice
A Chartered Tax Adviser can identify savings, prevent mistakes and protect you from HMRC penalties.
How Maratax Can Help
Based in Frimley, Maratax provides specialist Self-Assessment support for individuals, landlords, sole traders and company directors across Surrey, Hampshire and Berkshire.
With decades of experience and a friendly, approachable style, we make the process straightforward and stress-free. For expert self-assessment support, contact Maratax today to arrange a consultation.
