Introduction
Tax deadlines can catch people out, especially if you’re self-employed, a landlord, a company director or running a growing business. Missing a tax return deadline often means automatic penalties — even if you owe no tax.
At Clarus Accountancy Group, we help clients across Northamptonshire, Bedfordshire, Hertfordshire and Buckinghamshire stay compliant, avoid fines, and file on time with confidence.
This article breaks down the exact deadlines you need to know.
Self-Assessment Tax Return Deadlines
If you’re required to file a Self-Assessment tax return (SA100), there are two key deadlines:
1. Paper Tax Returns – 31 October
If you file a paper form by post, HMRC must receive it by midnight on 31 October following the end of the tax year.
2. Online Tax Returns – 31 January
Online tax returns must be submitted by midnight on 31 January.
This is the most common filing method, and Clarus can submit this on your behalf using secure HMRC-recognised software.
Tax Payment Deadlines
There are two possible payments:
1. Balancing Payment – 31 January
You must pay any tax owed for the previous tax year by this date.
2. Payment on Account – 31 July (if applicable)
If you earn above a certain threshold, HMRC may require advance payments towards next year’s bill.
Who Needs to File a Tax Return?
You need to file if you are:
✔ Self-employed
✔ Earning rental income
✔ A company director
✔ Receiving dividends
✔ A higher-rate taxpayer
✔ A subcontractor under CIS
✔ Someone with untaxed income
Not sure if you need to file? Clarus can advise.
What Happens If You Miss the Deadline?
HMRC may issue penalties even if:
❌ You owe no tax
❌ You didn’t know you had to file
❌ You filed late by only a few days
Penalties include:
- £100 automatic fine
- Additional penalties at 3, 6 and 12 months
- Interest on unpaid tax
Our team helps ensure this never happens.
How Clarus Accountancy Group Helps You File On Time
We take the stress out of the entire tax process by offering:
💼 Full Self-Assessment service
From bookkeeping to filing, we handle everything.
🗂️ Digital record-keeping
MTD-ready solutions with Xero, Sage and QuickBooks.
🕒 Deadline reminders
Never miss a submission again.
📍 Local expertise for:
- Northamptonshire
- Bedfordshire
- Hertfordshire
- Buckinghamshire
Final Thoughts
Filing your tax return on time is essential to avoid unnecessary penalties and maintain good financial standing. With Clarus Accountancy Group handling your tax affairs, you get peace of mind, accuracy, and year-round financial support.
Need help with your next tax return?
📞 Reach out today — we’ll get everything filed correctly and on time.