Skip to main content
Making Tax Digital

MTD Quarterly Reporting: Deadlines, Preparation & Common Mistakes

A practical guide to quarterly updates under Making Tax Digital. When to submit, what to include, how to prepare, and how to avoid the mistakes that trigger penalties.

Quick Summary

Under MTD for ITSA, you submit four quarterly updates and one final declaration each tax year. Each quarterly update summarises your income and expenses for that period. Updates are due by the 7th of the month following each quarter end.

Quarterly Reporting Deadlines

The tax year (6 April to 5 April) is split into four quarters. Each quarter has a submission deadline one month and two days after the quarter ends:

QuarterPeriodSubmission Deadline
Q16 April – 5 July7 August
Q26 July – 5 October7 November
Q36 October – 5 January7 February
Q46 January – 5 April7 May

Final Declaration

After your fourth quarterly update, you submit a final declaration by 31 January of the following year. This is similar to a Self Assessment tax return — it confirms your total income, expenses, allowances, and tax due for the year.

What's Included in Each Quarterly Update

Each quarterly update is a summary — not a line-by-line list of every transaction. You report:

  • Total income for the quarter (all invoices issued or income received)
  • Total expenses by category (e.g., travel, materials, office costs, subcontractor payments)

Your MTD software calculates an estimated tax position after each update, giving you a running picture of what you'll owe at year end.

How to Prepare Quarterly Updates

Preparation is the difference between a 5-minute submission and a stressful scramble. Here's how to stay on top of it:

Step-by-Step Preparation

1. Keep Records Up to Date Throughout the Quarter

Don't wait until the deadline. Record income and expenses as they happen — ideally weekly. If you're invoicing through software like Experi, your income records are created automatically.

2. Reconcile Your Records

Before submitting, check your records against your bank statements. Make sure all income and expenses are accounted for and correctly categorised.

3. Categorise Expenses Correctly

HMRC expects expenses in standard categories. Consistent categorisation throughout the year prevents errors and reduces time spent on each quarterly update.

4. Review the Summary Before Submitting

Your software will generate a summary of income and expenses. Review the figures and check they look reasonable before hitting submit. Does total income match what you expect? Are any expense categories unusually high or low?

5. Submit Before the Deadline

Don't leave it to the last day. Submit a few days early to avoid technical issues or last-minute problems. Set calendar reminders for a week before each deadline.

Common Mistakes to Avoid

These are the errors that most commonly trigger penalties or create problems:

Missing Deadlines

The most obvious mistake but the most common. Each late submission earns a penalty point. Set reminders for every deadline — don't rely on your memory for five submissions per year.

Leaving Everything to Quarter End

If you haven't recorded transactions during the quarter, you'll spend hours reconstructing your records. This leads to errors, missing transactions, and late submissions.

Mixing Personal and Business Expenses

Only claim allowable business expenses. Mixing personal spending into your quarterly updates can trigger HMRC inquiries. Use a separate business bank account to keep things clear.

Incorrect Categorisation

Putting expenses in the wrong category won't necessarily change your tax, but inconsistent categorisation makes it harder to spot errors and may raise questions from HMRC.

Forgetting Unpaid Invoices

Whether you report on a cash basis (when paid) or accruals basis (when invoiced) affects which invoices to include. Know your accounting basis and be consistent.

Cash Basis vs Accruals Basis

How you report income in quarterly updates depends on your accounting basis:

Cash Basis

Report income when received and expenses when paid.

  • • Invoice sent in March, paid in April → report in Q1
  • • Simpler for most sole traders
  • • Default method for small businesses
  • • Available if turnover is under £150,000

Accruals Basis

Report income when invoiced and expenses when incurred.

  • • Invoice sent in March, paid in April → report in Q4 of previous year
  • • Better for complex businesses
  • • Required if turnover exceeds £150,000
  • • More accurately matches income to work done

How Good Invoicing Practices Make Quarterly Reporting Easier

Your invoicing habits directly affect how smooth quarterly reporting is:

Invoice Promptly

Sending invoices as soon as work is completed means your income records are always up to date. No scrambling to remember unbilled work at quarter end.

Use Consistent Descriptions

Clear, consistent invoice descriptions make categorisation straightforward. If your invoices clearly state the type of work or product, classifying income becomes automatic.

Track Payment Status

Knowing which invoices are paid and which are outstanding is essential — especially if you use the cash basis. Software that tracks payment status saves you cross-referencing bank statements manually.

Use Software, Not Paper

Digital invoicing software creates the records MTD requires automatically. Every invoice is timestamped, stored, and searchable — ready to export for quarterly reporting.

Setting Up a Quarterly Routine

Build a simple routine to stay on top of quarterly reporting:

Weekly

Record any income and expenses not already captured by your invoicing software. File receipts for business expenses.

Monthly

Reconcile your records against your bank statement. Check for any missing invoices or unrecorded expenses.

Quarter End

Review your summary, check categorisation, and submit your quarterly update at least 3–5 days before the deadline.

Year End

Review the full year, make any adjustments, claim allowances, and submit your final declaration by 31 January.

Make Quarterly Reporting Effortless

Experi keeps your income records up to date automatically. Every invoice you send is stored digitally with the details you need for quarterly reporting. Spend less time on admin, more time on your business.

Start Free — No Credit Card Required

Frequently Asked Questions

What are the MTD quarterly reporting deadlines?

The deadlines are: Q1 (6 April – 5 July) due by 7 August, Q2 (6 July – 5 October) due by 7 November, Q3 (6 October – 5 January) due by 7 February, Q4 (6 January – 5 April) due by 7 May. The final declaration is due by 31 January of the following year.

What happens if I submit a quarterly update late?

You receive one penalty point for each late submission. Once you reach 4 points (the threshold for quarterly obligations), you receive a £200 penalty. Every subsequent late submission also triggers a £200 penalty. Points expire after 24 months of on-time submissions.

Do quarterly updates need to be exact?

Quarterly updates are summaries of income and expenses, not full tax returns. HMRC has confirmed that reasonable estimates are acceptable if exact figures aren't available, as long as you correct any inaccuracies in later updates or the final declaration. However, the closer to accurate your figures are, the fewer corrections you'll need.

Can I correct a quarterly update after submitting?

Yes. You can amend a submitted quarterly update. Any corrections or adjustments can also be made in subsequent quarterly updates or in your final declaration. The final declaration is where your overall tax position is confirmed and any discrepancies are resolved.

Related Resources

Ready to Get Started?

Create professional invoices in under 60 seconds with Experi.

View Pricing