Filing your Self Assessment Tax Return doesn’t have to be stressful. In this guide, we’ll walk you through the full process of submitting your 2024/25 return if you’re self-employed — including registration, tracking income, claiming expenses, and avoiding common errors.
Step 1: Registering for Self Assessment
If this is your first time filing:
- You must register by 5th October 2025 following the end of the tax year.
- You’ll need:
- National Insurance number
- Business details (trading name, start date)
- Government Gateway ID (create one if you haven’t)
- Register for UTR number to start Self Assessment with Tax2U
Step 2: Keep Accurate Records
You must keep records of:
- Income (invoices, receipts, bank statements)
- Allowable expenses (see below)
- Mileage logs or travel records
Tax2U Tip: Keep records for at least 5 years after the 31st January submission deadline.
Step 3: Claim Your Allowable Expenses
Reduce your tax bill by deducting:
- Home office use
- Work-related travel
- Tools and equipment
- Business insurance
- Phone and internet
- Accountant or software fees
Step 4: Complete the Return Online
Once you receive your UTR number:
- Select one of the Tax2U services and create an account
- Select the year for ‘Self Assessment’ → ‘File return’
- Follow each section carefully:
- Income summary
- Expenses claimed
- Tax already paid (e.g. CIS deductions)
Step 5: Submit and Pay
- Deadline: 31 January 2026
- Payment methods: Bank transfer, card, Direct Debit
- You’ll receive a confirmation email upon submission
Completing your return early means:
- No deadline panic
- More time to budget for tax
- Avoiding interest or penalties
Want us to do it for you? Start your Self Assessment with Tax2U