Submitting your Self Assessment Tax Return

When do I need to submit my Self-Assesment Tax Return?

The deadline for submitting your Self-Assessment Tax Return to HMRC depends on how you file:

• Paper returns: Must be submitted by 31 October following the end of the tax year.

• Online returns: Must be submitted by 31 January following the end of the tax year.

For example, for the 2023/24 tax year (which ended on 5 April 2024):

• Paper submission deadline: 31 October 2024

• Online submission deadline: 31 January 2025

If you owe tax and want HMRC to collect it through your tax code (if you’re employed or receive a pension), you must submit your return by 30 December.

If you miss the deadline, you may face penalties. Let me know if you need help with anything specific!

How do I submit my Self Assessment?

You can submit your Self-Assessment Tax Return online or by paper. Here’s how to do it:

1. Register for Self-Assessment

If this is your first time filing a tax return, you need to register with HMRC before you can submit it.

• Self-employed: Register by 5 October following the end of the tax year.

• Other income (e.g., landlord, dividends): Also register by 5 October.

• HMRC will send you a Unique Taxpayer Reference (UTR) and set up your Government Gateway account.

2. Gather Your Information

You’ll need:

• Your UTR number and Government Gateway login

• National Insurance number

• Income details (e.g., employment income, self-employment earnings, rental income, dividends)

• Expenses you want to deduct

• P60/P45 (if you were employed)

• P11D (if you had job benefits like a company car)

• Any tax already paid

3. Submit Your Return

Online Submission (Recommended)

1. Go to HMRC’s website and log in.

2. Select “Self Assessment” and follow the steps.

3. Enter your income and expenses.

4. Double-check your details.

5. Submit the return and save the confirmation.

Paper Submission (Not Recommended)

1. Download the SA100 tax return form from HMRC’s website.

2. Fill it in manually.

3. Post it to HMRC before 31 October.

4. Pay Any Tax Due

• You must pay any tax owed by 31 January.

• If your bill is over £1,000, you may need to make Payments on Account for the next tax year.

• You can pay via bank transfer, direct debit, debit/credit card, or cheque.

Late Filing Penalties

• Missed deadline (31 Jan): £100 fine.

• 3 months late: £10 per day (up to £900).

• 6 months late: 5% of tax due or £300 (whichever is higher).

How do I calculate my taxable profit?

What expenses can I claim on my self-assessment?

If you’re self-employed, you can deduct certain allowable expenses from your income before paying tax. These expenses must be wholly and exclusively for business use.

Common Allowable Expenses

1. Office & Admin Costs

• Business rent & utilities (if you rent an office/workspace)

• Phone, internet, and software costs

• Stationery, printing, and postage

• Advertising and marketing (e.g., website costs, social media ads)

2. Travel & Vehicle Costs

• Fuel, parking, and tolls for business trips

• Vehicle insurance, servicing, and repairs (if used for work)

• Public transport, flights, and accommodation for business trips

• Mileage (if using a personal vehicle for work) – 45p per mile for the first 10,000 miles, 25p after

3. Home Office Costs (If You Work from Home)

• A proportion of rent/mortgage interest, heating, electricity, and broadband

• Simplified option: Claim £10–£26 per month based on hours worked at home

4. Staff & Subcontractor Costs

• Employee wages and salaries

• Pensions and National Insurance contributions

• Subcontractor costs (e.g., if using freelancers)

5. Equipment & Tools

• Laptops, phones, and office furniture

• Business-related tools and machinery

• Software subscriptions (e.g., accounting software, design tools)

6. Stock & Materials

• Raw materials and goods for resale

• Packaging and delivery costs

7. Professional Fees

• Accountant, solicitor, or financial advisor fees

• Business insurance (e.g., public liability, professional indemnity)

8. Training & Education

• Training courses relevant to your business

• Books and subscriptions (if related to your work)

What You CAN’T Claim

• Personal expenses (e.g., holidays, clothes, food unless for business meetings)

• Fines or penalties

• Home costs unrelated to business (e.g., full rent or mortgage)

Would you like help calculating your expenses or working out your tax? Contact us now to discuss your bookkeeping & tax return needs

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