Every deadline, every penalty, and every way to avoid them. Bookmark this page.
The Deadlines at a Glance
Your tax year runs from 6 April to 5 April. Under MTD, you have the following deadlines:
Quarterly Update Deadlines:
Quarter | Period | Deadline to Submit |
|---|---|---|
Quarter 1 | 6 April – 5 July | 7 August |
Quarter 2 | 6 July – 5 October | 7 November |
Quarter 3 | 6 October – 5 January | 7 February |
Quarter 4 | 6 January – 5 April | 7 May |
Final Declaration: Also due by 31 January following the end of the tax year. This replaces the Self Assessment tax return and confirms your final tax position.
So for the 2026–27 tax year (April 2026 to April 2027), your final Declaration would be due by 31 January 2028.
Late Submission Penalties
HMRC uses a new points-based penalty system for MTD:
Each time you miss a quarterly deadline, you receive one penalty point.
Once you accumulate a set number of points (the threshold depends on how often you need to file — for quarterly filers, it's typically 4 points), you receive a £200 penalty.
Every further late submission after that also triggers a £200 penalty.
Points expire after a period of compliant behaviour (typically 24 months of on-time submissions), and your counter resets.
The key thing: the first few late submissions result in points, not immediate fines. It's a warning system. But once you hit the threshold, every subsequent late filing costs you £200.
Late Payment Penalties
If you don't pay the tax you owe on time:
After 15 days: | A penalty of 3% of the outstanding tax (4% from April 2027) |
After 30 days: | An additional 3% of the outstanding tax (4% from April 2027) |
After 31 days and ongoing: | A daily penalty at an annualised rate of 10% of the outstanding amount |
Plus, interest is charged on the unpaid amount from the original due date until payment is made.
These penalties add up quickly. A £5,000 tax bill that's 60 days late could incur over £365 in penalties and interest.
How RentalBux Helps You Avoid Penalties
Automatic deadline reminders. RentalBux sends you email and push notifications well in advance of each quarterly deadline and the year-end deadlines.
Dashboard countdown. Your dashboard shows when your next submission is due and how many days you have left.
Ready-to-submit indicators. When your quarterly figures are complete and ready to submit, RentalBux tells you — so you can file early and not worry about it.
Submission history. You can see exactly when each past submission was made, confirming you were on time.
If you keep your income and expenses up to date throughout the quarter and submit when RentalBux tells you it's ready, you'll never receive a penalty point.
Tips to Stay on Top of Deadlines
Set up push notifications on the RentalBux mobile app
File early — don't wait until the deadline day
Keep records up to date — spending 10 minutes a week logging transactions means you're always ready to submit
Add deadlines to your personal calendar as a backup
Related guides:
Filing Your First Quarterly MTD Submission
MTD for Income Tax — Complete Beginner's Guide