Self-Assessment for Security Workers: A Simple Guide (2025)

If you work in the UK security industry — as a door supervisor, CCTV operator, event steward, or security contractor — you might need to complete a Self-Assessment tax return each year.

Here’s how to get it right without stress (and without overpaying HMRC).

✅ Who Needs to File a Self-Assessment

You must file a Self-Assessment if you’re:

Self-employed (sole trader, freelancer, or subcontractor)
Earning extra income outside PAYE (for example, cash-in-hand work or private event shifts)
A company director taking dividends or director’s pay

If you’re paid through PAYE (e.g. on an agency payroll) and have no extra earnings, you usually don’t need to file.

📅 Key Deadlines for 2025

Task	Deadline
Register for Self-Assessment	5 October 2025
Submit online tax return	31 January 2026
Pay any tax owed	31 January 2026

Miss these dates and HMRC will fine you £100 minimum, even if you owe no tax.

🧾 Tracking Your Income and Expenses

Keep records of:

Shift payments (agency or direct)
Private event work
Any equipment purchases (radios, bodycams, uniforms)
Training costs (e.g. SIA renewal, first aid)
Travel and mileage
Public liability insurance

You don’t need fancy software, but it helps.

🔗 Read next: Best Free Accounting Tools for Security Professionals →

👨‍💻 How to File Your Self-Assessment Online

Go to gov.uk/log-in-register-hmrc-online-services
Create or log in with your Government Gateway ID
Fill out your income and expenses for the tax year (6 April to 5 April)
Check the summary and submit
Pay any tax owed by card or bank transfer

⚠️ Common Mistakes to Avoid

Forgetting to include training or travel costs
Not saving for tax during the year
Missing the January deadline
Using personal bank statements with no record of income split

Set aside around 20–25% of your income for tax and NI to stay safe.

🧮 How Much Tax Will You Pay?

For 2025/26:

Personal Allowance: £12,570 (no tax up to this)
Basic Rate: 20% on £12,571 – £50,270
Class 2 NI: £3.45/week (if profits > £12,570)
Class 4 NI: 9% on profits £12,570–£50,270

HMRC’s calculator or software like QuickBooks can estimate this automatically.

✅ Final Checklist

Before January rolls around:

Register with HMRC as self-employed
Keep a digital record of income and expenses
Save 20–25% of each payment for tax
File and pay before 31 January

Doing it right the first time saves stress — and keeps you in good standing for future contracts or company work.

Want More Guidance?

Visit the Self-Employed & Small Business Security Resources UK Homepage

Security Business Resources