Step-by-Step Guide: How to Submit Your Tax Returns Online in the UK
TAXNEWS
Submitting your tax return can feel overwhelming, especially if you're doing it for the first time. But the good news? The UK’s online HMRC system makes the process easier than ever. Whether you're self-employed, earning from investments, or need to declare additional income, this guide breaks everything down into simple, actionable steps.
By the end, you’ll know exactly how to submit your tax returns smoothly and avoid common mistakes.
Who Needs to Submit a Tax Return?
You may need to submit a Self Assessment tax return if you:
Are self-employed
Earn income not taxed at source (e.g., rental income, crypto, investments)
Receive dividends or operate as a company director
Earn above £100,000
Have overseas income
If you’re unsure, HMRC’s online checker can help, but when in doubt, it’s better to file.
Before You Start: Documents You’ll Need
Gather these to speed up your tax returns submission:
Your Government Gateway ID
UTR (Unique Taxpayer Reference) number
Income records (invoices, salary slips, rental statements, investment summaries)
Expense receipts (if you’re self-employed)
Bank statements
Pension contributions
Student loan details (if applicable)
Step-by-Step: How to Submit Your Tax Returns Online
1. Register for Self Assessment (if you haven’t already)
Visit the HMRC website
Create a Government Gateway account
Receive your UTR number by post (takes up to 10 days)
2. Log in to Your HMRC Account
Go to the HMRC portal and sign in with your Government Gateway ID and password.
3. Start a New Tax Return
Click on “Self Assessment”
Choose the relevant tax year
Begin the online form
4. Enter Your Personal Information
Confirm your details such as full name, address, and employment status.
5. Report Your Income
Fill in the sections that apply to you:
Self-employment income
Salary from employment
Rental income
Dividends
Capital gains
Crypto or foreign income
Make sure the numbers match your records.
6. Add Allowable Expenses
If you’re self-employed, claim eligible costs such as:
Office supplies
Travel
Utilities (if working from home)
Marketing & software
Professional fees
Including these reduces the tax you owe.
7. Review the Summary
HMRC will calculate:
Total taxable income
Allowances
Deductions
Tax owed or refund due
Double-check all figures carefully.
8. Submit Your Return
Once satisfied, submit your tax return online.
You’ll receive an on-screen confirmation from HMRC.
9. Pay Your Tax Bill
The deadline to pay is 31st January 2026
You can pay via:
Bank transfer
Debit card
Direct Debit
Online banking
Tips to Avoid Mistakes
Don’t leave submission until the last minute
Keep receipts and records for at least 5 years
Use accurate figures, avoid estimates where possible
Update your contact details in HMRC
Check which income types are taxable and which are exempt
Need Help? We’ve Got You.
Tax forms can be confusing, but you don’t have to handle them alone.
Book online assistance for your tax submission with Boobooks
Our team helps you complete the process error-free, on time, and with full compliance.