What is Self Assessment? Tax System Explained (Without the Boring Bits!) 
Self Assessment is HMRC’s way of saying “Hey, you need to sort out your own taxes!” – it’s like being given the keys to the family car, exciting but terrifying! 
How It Works (The Simple Version!) 
Most employees have tax deducted through PAYE (Pay As You Earn) – their employer does the heavy lifting! 
Self Assessment is for everyone else who doesn’t have this luxury.
Under Self Assessment, you’re the boss of:
- Calculating your tax liability (maths time!)
- Reporting all income sources (yes, even that £50 from selling old clothes!)
- Claiming allowable deductions (every penny counts!)
- Paying any tax due on time (no extensions, no excuses!)
Who Needs to File? (Are You One of Us?)
The MOST common reasons include but are not limited to:
- Being self-employed earning over £1,000
- Have rental income (landlord life!)
- Have other untaxed income such as dividends
- Need to pay Capital Gains Tax (sold something profitable!)
- Receive Child Benefit and earn above a certain level
The Process (Your Tax Journey!)
- Register
– Get your Unique Taxpayer Reference (UTR) – it’s like your tax ID card! 2. Keep records 
– Hoard those receipts like a tax dragon! 3. Complete return 
– File online by 31st January (no pressure!) 4. Pay tax 
– Settle any amount due by 31st January
Tax Year Dates (Because Nothing’s Simple!) 
The UK tax year runs from 6th April to 5th April (why not January to December? Because that would be too easy!) 
You file your 2024/25 tax return (covering 6 April 2024 to 5 April 2025) by 31st January 2026.
Not sure if you need to file? Use HMRC’s online checker tool or consult an accountant like us – we love this stuff!
“Disclaimer: Paul Stankiewicz is the owner and principal at Paul Marks & Co Chartered Accountants which is the trading name of Paul Marks Ltd a Limited Company registered in England and Wales (registered number 4487645).This article is designed for the information of readers only and is the opinion of the author only. Readers should not act on any of the information contained in this article without seeking professional advice. Nothing in this article constitutes advice, nor does the transmission, downloading or sending of any information or the Material create any contractual relationship. Links to third party websites are provided as a convenience to the reader, Paul Marks Ltd does not control and is not responsible for any of those websites or their content. Paul Stankiewicz and Paul Marks Ltd accepts no liability or responsibility whatsoever for any loss or damage suffered by any user of the information contained on or accessed through this article or the Material downloaded.
