UK Tax Calendar for 2024–25: Key Deadlines for Self-Assessment

The UK tax system can feel like a maze—especially if you're newly self-employed, a side hustler, landlord, freelancer, or anyone earning untaxed income. As the financial year rolls on, knowing your deadlines is half the battle.

Welcome to your official Self Assessment tax calendar for 2024–25, updated to reflect the latest HMRC rules, payment dates, and filing expectations. Whether you're filing for the first time or you’ve done this before, let Zipptax help you file smarter, avoid fines, and reclaim peace of mind.

 Key Tax Dates for the 2024–25 Self Assessment Cycle

Let’s walk through each important deadline—and what you need to do before it arrives.

 6 April 2024 – Start of the 2024–25 Tax Year

This is the first day you should begin tracking your:

• Invoices and income
• Receipts and expense records
• Donations, pension contributions, student loan repayments

Starting early = less stress when it’s time to file. Zipptax offers a downloadable checklist to help you stay organised from day one.

 5 October 2024 – Register for Self Assessment (if you’re new)

Are you newly self-employed or earning from side income (like Airbnb, tutoring, crypto, or dividends)? Then you must register with HMRC by 5 October.

• Once registered, you’ll receive your Unique Taxpayer Reference (UTR)
• HMRC will also assign your Personal Tax Account for managing submissions

 Zipptax handles registration if you’re unsure where to begin—and yes, we remind you of every milestone after that.

 31 October 2024 – Deadline to File Paper Returns

Still filing your tax return the traditional way? Then this is your cutoff date.

• Paper returns must arrive at HMRC by this date (not just be posted)
• Missing it means switching to online—and risking penalties if you’re late

But let’s be real: online filing is faster, safer, and gives you until January 31. Zipptax handles it all for you securely online, so you never miss a beat.

 31 January 2025 – Final Deadline for Online Returns

This is the big one: the last day to file your return and pay any tax owed for the 2023–24 tax year.

If you miss it:

• Immediate £100 penalty
• Fines increase over time
• Interest begins accumulating daily

 With Zipptax, you can file months in advance and still pay later. We’ll even estimate your bill in October so you can budget calmly. If you’ve received an unexpected tax bill after missing a deadline, here’s how to fix HMRC tax bill errors step-by-step.

 31 January 2025 – First “Payment on Account” (if applicable)

If your tax bill last year was over £1,000, HMRC expects advance payments for the upcoming tax year, split in two parts.

Due today:

• 50% of estimated bill for 2024–25
• Zipptax calculates this for you automatically during filing

 28 February 2025 – First Penalty Milestone

Still haven’t filed your return? You’ll now face:

Missed Filing Time - Penalty

1 day late - £100 fine (automatic)

3 months late -£10/day (up to £900)

6 months late -£300 or 5% of unpaid tax

12 months late - Additional £300 or 5%

It adds up fast. But don’t panic—Zipptax helps clients file even after the deadline, minimising penalties and interest.

 31 July 2025 – Second Payment on Account Due

Your second installment for 2024–25 taxes is now due—unless you filed early and HMRC adjusted your payments.

 Missing this date can trigger interest charges. Set a reminder—or let Zipptax track it and notify you ahead of time.

 Who Needs to File a Self Assessment Tax Return?

You likely need to file if you:

• Are self-employed or a freelancer
• Earn income through rental property, dividends, or crypto
• Work in the gig economy (Uber, Deliveroo, Etsy, etc.)
• Have earned over £1,000 outside PAYE
• Are a partner in a business partnership
• Claimed Child Benefit but earn over the high-income threshold (£50,000+)
• Need to claim tax reliefs (pension contributions, expenses, etc.)

 Not sure? Zipptax’s free eligibility quiz can confirm in under 60 seconds.

 What You’ll Need to Prepare

Before you file, gather:

• National Insurance number
• Unique Taxpayer Reference (UTR)
• Records of all income (invoices, salary, rent, investments, etc.)
• Expense receipts and bank summaries
• P60 or P45 (if you were employed during the year)
• Student loan, pension, or charitable donation info

 Zipptax’s checklist tool helps you compile everything you need—and flags what’s missing before you file.

 Why Filing Early Is Always Better

While 31 January is the final day, early filers enjoy:

• Peace of mind during the holidays
• Faster refunds if HMRC owes you money
• More time to ask questions and fix issues
• Extra breathing room to budget for payment
• Less risk of fraud, which often spikes near the deadline

 With Zipptax, the whole process takes about 30 minutes of your time—and we do the rest.

 What Zipptax Does for You For just £149, Zipptax:

• Registers you with HMRC (if needed)
• Collects and reviews all your tax documents
• Identifies all possible deductions and reliefs
• Calculates your tax bill
• Files your Self Assessment securely
• Follows up with HMRC and tracks your refund
• Reminds you about Payments on Account and future deadlines

No stress. No jargon. No late-night Google searches.

 Quick Reference Table: 2024–25 Self Assessment Timeline

DateEvent Description Action Needed

6 April 2024 Start of 2024–25 tax year Begin tracking income & expenses

5 October 2024 Deadline to register for Self Assessment Register with HMRC if you're new

31 October 2024 Paper filing deadline File by post (or file online for longer)

31 January 2025 Final deadline for online return & first payment Submit & pay tax owed

28 February 2025 Penalties begin for late returns Additional fines apply

31 July 2025 Second “payment on account” due Pay your second instalment

 Final Thoughts: Plan Now, Relax Later

You’ve got enough on your plate—your tax return doesn’t need to be another source of stress. By tracking deadlines, filing early, and using support from Zipptax, you’ll be ahead of the curve and in control of your finances.

 Let Zipptax take care of your 2024–25 Self Assessment—so you can focus on what really matters.

FAQs:

 1.When does the UK tax year 2024–25 start and end?

The tax year starts on 6 April 2024 and ends on 5 April 2025. Income earned during this period must be reported on your next Self Assessment tax return.

 2.What is the deadline to register for Self Assessment?

If you’re self-employed or have income outside PAYE, you must register with HMRC by 5 October 2024 to file for the 2023–24 tax year.

 3.When is the online tax return due for 2023–24?

The deadline to submit your online Self Assessment return is 31 January 2025. This is also the final date to pay any tax owed for the previous tax year.

 4.What happens if I file my return late?

If you miss the deadline, HMRC charges:

• £100 immediately
• £10/day after 3 months (up to £900)
• £300 or 5% of the tax owed after 6 months
• Additional penalties after 12 months

 5.Can I pay my tax bill in instalments?

Yes. If your tax bill is over £1,000, HMRC expects Payments on Account—50% by 31 January and 50% by 31 July. You may also set up a payment plan via HMRC if needed.

 6.Who needs to file a Self Assessment tax return?

You must file if you’re:

• Self-employed or a freelancer
• A landlord or earn untaxed rental income
• Receiving dividends, crypto earnings, or overseas income
• Earning more than £1,000 outside PAYE
• Claiming tax reliefs or repaying student loans through Self Assessment

 7.What documents do I need to file?

You’ll need:

• National Insurance number
• Unique Taxpayer Reference (UTR)
• Income records (invoices, salary, rent, dividends)
• Expense receipts and deductions
• P60/P45, bank statements, student loan or pension info

 8.Why is it better to file early?

Filing early helps:

• Avoid HMRC penalties and interest
• Claim refunds faster
• Budget ahead for payment
• Protect against tax fraud and system delays