You must send quarterly updates to HMRC as part of Making Tax Digital (MTD) for Income Tax. These updates report your income and expenses and form the basis of your end of year tax return.

There are two types of quarterly submission periods:

• Standard period – Runs from 6 April to 5 April each year
• Calendar period – Runs from 6 April to 31 March in the first year, then from 1 April to 31 March each year after
  (Only select this if your accounting start date is 1 April)

If you use the calendar period, transactions dated 1 April 2025 to 5 April 2025 aren’t included in the update or tax calculation in the first year. HMRC advises adding these as a Business Source Adjustment Summary (BSAS) at year end. 

You can only change your submission period before you send your first update to HMRC.

1. From the Income Tax summary page, select Manage business details.
2. Select Switch to standard period or Switch to calendar period.
3. Review the message that explains how the change will affect your submissions.
4. Confirm your choice.

Your business will now follow the selected period dates for quarterly submissions.