If you’re self-employed in the UK, you’ll often hear references to submitting an “annual report.” For sole traders and business partners, this term typically refers to your Self Assessment tax return—the Form SA100 that you must complete and submit to HMRC each year. This comprehensive guide walks you through everything you need to know about filing your self-employed annual report in 2025.
Who Needs to File a Self-Assessment Tax Return?
Not everyone needs to complete a Self Assessment, but you’ll certainly need to file one if you fall into any of these categories:
- You’re a sole trader with income over £1,000 from self-employment
- You’re a business partner in a partnership
- You have untaxed income from property, investments, or dividends exceeding certain thresholds
- You’re a company director (unless it’s a non-profit organisation and you didn’t receive payment)
- Your total income exceeded £150,000
- You need to pay the High Income Child Benefit Charge
Even if you earn less than £1,000 from self-employment, you may still choose to file voluntarily to claim tax reliefs or build up National Insurance credits.
Key Deadlines for 2025
Missing these deadlines can result in automatic penalties, so mark them clearly in your calendar. For the 2024/25 tax year, here are the critical dates:
- 5 October 2025: Registration deadline if you’re new to Self Assessment
- 31 October 2025: Deadline for submitting paper tax returns
- 31 January 2026: Deadline for online tax returns and payment of any tax owed
Most people file online—in fact, 97% of Self Assessment returns are now submitted digitally through HMRC’s online portal. The digital route gives you an extra three months to file and automatically calculates your tax bill.
What You Need to Report
Your Self Assessment tax return requires comprehensive information about all your income sources and allowable expenses. You’ll need to report:
- Self-employment income and business expenses
- Property rental income
- Dividends and interest from savings and investments
- Any other untaxed income
Gathering this information correctly is the first step to accurate filing. You’ll need to keep detailed records, including invoices, receipts, bank statements, and mileage logs for at least five years. If you’d prefer to have an expert handle your personal tax filing, professional accountants can manage the entire process for you, from document review to final submission.
How to File Your Return
HMRC offers two methods for submitting your Self Assessment:
Online Filing: This is by far the most popular option, used by the vast majority of taxpayers. You’ll need to register for a Government Gateway account, which gives you access to HMRC’s online services. The system guides you through each section and automatically calculates your tax liability.
Paper Filing: If you prefer traditional methods, you can request and complete a paper SA100 form. Remember that the deadline is three months earlier than for online submissions.
If you’re self-employed, you’ll also need to complete the SA103F (full version) supplementary page for self-employment. This form is required if your annual turnover exceeds the VAT registration threshold or if you need to report certain expenses and capital allowances in detail.
Important Changes for 2024/25
The 2024/25 tax year marks the full implementation of the tax year basis for reporting self-employment profits. Previously, sole traders and partners could choose an accounting period that didn’t align with the tax year (6 April to 5 April). Under the new rules, you must report profits that arise within the actual tax year itself.
This change simplifies the system and makes it easier to understand which profits belong to which tax year. If you’re affected by this transition, you may have had overlap relief or transitional adjustments in the 2023/24 tax year.
Paying Your Tax Bill
Your Self Assessment will calculate how much you owe, which typically includes:
- Income Tax on profits above your Personal Allowance (£12,570 for 2024/25)
- Class 2 and Class 4 National Insurance contributions
- Any penalties or interest for late filing or payment
Additionally, the majority of self-employed people pay their taxes on account—that is, in advance. These are based on the liability from the prior year and are due on January 31 and July 31. If your circumstances change significantly, you can apply to reduce these payments.
Next Steps: Get Professional Support
Meeting your tax obligations as a self-employed professional involves navigating complex rules, keeping meticulous records, and meeting strict deadlines. For peace of mind and to ensure your self-employed annual report is accurate and filed on time, consider exploring dedicated Personal Tax and Self Assessment services. Professional accountants can handle the paperwork, identify all available tax reliefs, and ensure you remain compliant with HMRC requirements, allowing you to focus on growing your business with confidence.
