Quarterly Submission Deadlines Explained

Quarterly submissions are the heartbeat of Making Tax Digital. Instead of one annual return, you send HMRC four updates a year — and each one has its own deadline. Miss one and the points-based penalty system kicks in.

Here's how the quarterly cycle works, when your deadlines fall, and how to stay safely ahead of them.

How the quarterly periods work

Your quarterly periods are based on your accounting period, not the calendar year. If your accounting period starts on 6 April (the tax year start), your quarters run roughly:

• Quarter 1: 6 April – 5 July
• Quarter 2: 6 July – 5 October
• Quarter 3: 6 October – 5 January
• Quarter 4: 6 January – 5 April

If your accounting period starts on a different date, your quarters shift with it. AppyTax automatically works out your quarters from your accounting period so you never have to calculate them manually.

When each submission is due

The deadline for each quarterly update is normally one month plus seven days after the quarter ends. So for a quarter ending 5 July, the deadline is 12 August. For a quarter ending 5 October, it's 12 November — and so on.

Your final declaration is due separately, by 31 January after the tax year ends (the same date as the old Self Assessment deadline).

The points-based penalty system

HMRC uses a points-based system for late submissions. Each missed deadline adds a point to your record. The system works like this:

• Each late quarterly update earns one point.
• When you reach the points threshold for your filing frequency, you receive a £200 penalty.
• Further late submissions within the two-year expiry window can trigger additional £200 penalties.
• Points expire two years after they're issued, provided you stay on time in between.

For sole traders submitting quarterly, the threshold is relatively low — so a couple of missed deadlines can quickly turn into a fine. Automated reminders are the best protection.

What each quarterly update contains

Each update summarises your income and expenses for that quarter, drawn directly from your digital records. You don't need to calculate anything by hand — your software totals the figures and presents them for you to review and approve before they're sent to HMRC.

The update isn't a payment. It's a summary of how the quarter looked, which HMRC uses to track your position through the year. Your actual tax payments still fall on the usual Self Assessment dates.

How to never miss a deadline

The combination of a clear deadline calendar and proactive reminders makes late submissions almost entirely avoidable. AppyTax shows your next deadline front and centre, sends reminders by email and in-app as it approaches, and prepares your update in advance so you only need to review and submit.

Subscribe and your quarterly calendar will be set up automatically based on your accounting period.