MTD ITSA Quarterly Updates: Avoid Errors and Late Penalties

Who Needs to Submit Quarterly Updates?

If you are a sole trader or freelancer with total gross income from self-employment or property of more than £50,000 per year, MTD ITSA has applied to you since April 2026. Those earning above £30,000 join from April 2027. Quarterly updates replace the single annual Self Assessment return for your business income, meaning you now report income and expenses to HMRC four times a year through MTD-compatible software.

When Are the Quarterly Deadlines?

Each tax year is divided into four quarterly periods. For the 2026 to 2027 tax year, the submission deadlines are as follows:

• Quarter 1 (6 April to 5 July 2026): due by 7 August 2026
• Quarter 2 (6 July to 5 October 2026): due by 7 November 2026
• Quarter 3 (6 October to 6 January 2027): due by 7 February 2027
• Quarter 4 (7 January to 5 April 2027): due by 7 May 2027

You must also submit an End of Period Statement (EOPS) and a Final Declaration by 31 January 2028, which replaces the old Self Assessment tax return and is where you confirm your total taxable income for the year.

Common Filing Errors to Avoid

Most mistakes made during quarterly updates fall into a handful of predictable categories. Being aware of them now will save you time and stress later.

• Submitting estimated figures carelessly: Quarterly updates can include estimates, but HMRC expects them to be reasonable. Wildly inaccurate figures that are not corrected by your Final Declaration can attract scrutiny. Always use your actual records where possible.
• Forgetting to categorise expenses correctly: MTD-compatible software requires you to assign expenses to specific categories such as travel, office costs, or professional fees. Miscategorisation does not usually change your tax bill immediately, but it can cause problems during HMRC compliance checks.
• Missing a quarter entirely: Each quarterly update must be submitted even if you had no income or expenses that period. A nil return is still required. Omitting a quarter triggers the new points-based penalty system.
• Using non-compatible software: Only HMRC-recognised MTD software can submit quarterly updates. Spreadsheets are permitted only if used alongside approved bridging software. Check the HMRC approved software list before filing.
• Mixing personal and business transactions: Ensure your business bank account or records clearly separate personal spending. Including personal expenses in your quarterly update is a common error that can distort your figures significantly.

Understanding the Points-Based Penalty System

MTD ITSA operates a points-based late filing penalty system. Each missed quarterly deadline earns you one penalty point. Once you reach the threshold of four points, you receive a £200 financial penalty. Further late submissions after that point each carry an additional £200 charge. Points expire after 24 months if you maintain a clean filing record, but the key takeaway is that missing even one quarter has lasting consequences.

Late payment penalties work differently. If you pay your January tax bill late, you face a 3 percent charge on amounts outstanding after 30 days, rising to a further 3 percent after six months and an additional 10 percent per year after twelve months. Interest at the Bank of England base rate plus 4 percent also accrues from the payment due date.

Practical Steps to Stay on Track

• Reconcile your records monthly so quarterly submissions take minutes rather than hours.
• Set calendar reminders at least two weeks before each quarterly deadline.
• Use your software's tax estimate feature to set aside the right amount of tax throughout the year, reducing the risk of a large January payment catching you short.
• Submit early if your figures are ready. There is no benefit to waiting until the deadline.

MTD ITSA demands consistency rather than perfection. Build good habits now and quarterly updates will become a straightforward part of your working routine rather than a source of anxiety.