MTD for ITSA Penalties Explained: Points, Fines, and What Late Submission Actually Costs

Making Tax Digital for Income Tax Self Assessment went live on 6 April 2026 for sole traders and landlords earning over £50,000. With it came an entirely new penalty regime that replaces the old fixed-penalty model most people were used to.

The new system is built on two separate tracks: a points-based system for late submissions and a percentage-based system for late payments. They operate independently. You can be penalised for one, the other, or both at the same time.

This guide explains exactly how both work, with real numbers so you can see what is actually at stake. If you are an accountant managing dozens of clients through MTD, or a sole trader handling your own submissions, the mechanics are the same — and worth understanding before the first quarterly deadline arrives.

The points-based penalty system for late submissions

HMRC moved away from immediate fines for late filing. Instead, they introduced a penalty points system that works a bit like points on a driving licence. Each late submission adds one point to your record. Once you hit the threshold, you receive a £200 fixed penalty — and every subsequent late submission also triggers £200 until your record is clean.

How points accumulate

The penalty threshold depends on how often you are required to submit. For MTD for ITSA, you submit quarterly updates, so your threshold is 4 points.

• 1st late submission: 1 point. No fine.
• 2nd late submission: 2 points. No fine.
• 3rd late submission: 3 points. No fine.
• 4th late submission: 4 points. Threshold reached. £200 penalty.
• 5th and every subsequent late submission: £200 penalty each time.

Those four late submissions do not need to be consecutive. If you miss Q1 in your first year, submit Q2 and Q3 on time, then miss Q4, you still have 2 points. The points accumulate over time, not within a single tax year.

A worked example

Take Sarah, a freelance marketing consultant earning £65,000. She is in the first wave of MTD for ITSA from April 2026. Her quarterly submission deadlines are:

• Q1 (6 Apr – 5 Jul): due 5 August 2026
• Q2 (6 Jul – 5 Oct): due 5 November 2026
• Q3 (6 Oct – 5 Jan): due 5 February 2027
• Q4 (6 Jan – 5 Apr): due 5 May 2027

Sarah misses Q1 because she is still figuring out her software. She gets her Q2 in on time. She misses Q3 because January was busy. She files Q4 late because she forgot the May deadline.

Her points after year one: 3. No financial penalty yet, because the threshold is 4. But she is one missed deadline away from the £200 trigger.

In year two, she misses Q1 again. She now has 4 points and receives a £200 penalty. If she misses Q2 as well, that is another £200. The fines continue at £200 per late submission until she resets her points.

The points system is designed to give occasional mistakes a pass while catching persistent non-compliance. But four late submissions out of eight (two years of quarterly filings) is not hard to reach if your process is not solid.

The 2026/27 soft landing

HMRC has confirmed a soft landing for the first year. During the 2026/27 tax year, penalty points will still be recorded on your account, but the £200 fines will not be charged even if you hit the 4-point threshold.

This is genuinely useful breathing room. But it comes with a catch that is easy to overlook: the points themselves are still real. If you rack up 3 points in year one because you treated it as consequence-free, you start year two just one late submission away from a financial penalty. The soft landing is an opportunity to build good habits, not an excuse to delay them.

How to reset your penalty points

Points are not permanent, but clearing them requires sustained effort. For quarterly obligations, you need 24 consecutive months of on-time submissions with no outstanding returns. The clock starts from the month after your last late submission.

If Sarah has 4 points after missing a Q1 deadline in July 2027, she needs to file every single quarterly update on time from August 2027 through to August 2029 — two full years without a single late return — to get back to zero. If she misses one deadline during that period, the 24-month clock restarts.

This is strict. It means a pattern of occasional lateness can keep you at or near the threshold indefinitely. Getting ahead of your submissions is far cheaper than trying to catch up once points have accumulated.

Late payment penalties: a different system entirely

Late submission penalties are about whether you filed on time. Late payment penalties are about whether you paid on time. They are completely separate.

The late payment regime does not use points. It goes straight to money. There are three tiers:

• 15 days overdue: HMRC charges 2% of the outstanding tax amount.
• 30 days overdue: An additional 2% is charged on whatever remains unpaid at day 30. So the total first-month penalty can be up to 4% of the original debt.
• After 30 days: A daily rate of 4% per annum accrues on the outstanding balance until it is paid in full.

A worked example

David is a landlord with three buy-to-let properties. His annual tax bill through MTD for ITSA works out to £12,000. He owes a balancing payment of £3,000 after his Final Declaration, due 31 January 2028.

David does not pay until 15 March 2028 — 43 days late. Here is what he owes in penalties:

• Day 15: 2% of £3,000 = £60
• Day 30: Additional 2% of £3,000 = £60
• Days 31–43 (13 days): 4% per annum on £3,000 = £120/year = roughly £0.33/day × 13 = £4.27

Total late payment penalty: £124.27 on top of the £3,000 he already owed. That is 4.1% of the original amount for being 43 days late.

For larger tax bills, the numbers get uncomfortable quickly. A £20,000 balancing payment that is 60 days late incurs roughly £830 in penalties. Late payment interest (currently running at over 7% per annum) is charged on top of that, separately.

How the two penalty systems interact

The submission and payment penalties run in parallel. You can be hit by both at once. Consider this scenario:

A sole trader files their Q3 update two weeks late (1 penalty point) and also underpays their balancing payment by £5,000 for 45 days. They receive: one penalty point towards their submission threshold, plus late payment penalties of £200 (2% at day 15) + £200 (2% at day 30) + roughly £8 (daily accrual for 15 days). Total financial cost: £408 for that single period of non-compliance.

For accounting practices managing many clients, this compounds fast. If 50 clients each miss one quarterly deadline, that is 50 penalty points distributed across your client base. If those clients were already at 3 points, you are looking at 50 × £200 = £10,000 in aggregate fines across the practice.

What the old system looked like

Under the previous Self Assessment regime, the penalties were simpler but arguably less fair. Miss your filing deadline and you received an immediate £100 fine, regardless of whether it was your first offence or your fifth. Three months late added £10 per day for up to 90 days. Six months added the greater of £300 or 5% of the tax owed. Twelve months added another £300 or 5%.

The new system is more forgiving for occasional mistakes (you get three free passes before any fine) but harder on persistent lateness (once you hit the threshold, every late submission costs money, and clearing your record takes two years of perfect compliance).

Practical steps to avoid penalties

The easiest way to avoid the new penalty regime is to never be late. That sounds obvious, but MTD for ITSA creates four deadlines per year per client instead of one. For a practice with 200 affected clients, that is 800 quarterly deadlines to track annually. The margin for error is narrow.

• Automate the bookkeeping. The biggest bottleneck in quarterly submissions is not the filing itself — it is getting the books up to date in time to file. If you are manually processing invoices and bank statements, four times per year becomes unworkable. Tools like Briefcase Ledger use AI agents to process transactions continuously, so your records are always ready when the deadline arrives. No quarter-end rush, no catch-up. Read more about bookkeeping automation options.
• Set deadline reminders early. Do not aim for the deadline day. Aim for two weeks before. If Q1 is due 5 August, your internal target should be 22 July. This gives you a buffer for client delays, software issues, and the inevitable holiday overlap.
• Triage your client list now. Identify which clients are in the £50,000+ bracket for April 2026, which are £30,000+ for April 2027, and which are borderline. Knowing the phased rollout lets you stagger your preparation rather than trying to onboard everyone at once.
• Get clients filing from Q1. The soft landing tempts some to delay getting set up. Resist this. Using Q1 and Q2 of 2026/27 as no-penalty practice runs is exactly how the soft landing should be used — not as an excuse to skip them entirely and start with 0 points but no experience.

Frequently asked questions

Getting started

The first MTD for ITSA quarterly deadline is 5 August 2026 — barely four months away. If you have not set up your digital record-keeping and chosen your MTD software, now is the time. The penalty regime is designed to punish drift, not one-off mistakes. Build the habit early, use the soft landing period wisely, and automate what you can.

For a comparison of the software options available for MTD quarterly submissions, read our guide to MTD software for sole traders and landlords. For more on how Briefcase handles the bookkeeping behind MTD, including automated invoice processing and bank reconciliation, start a free trial or read about how AI agents are transforming accounting workflows.