HMRC updated its “How to report Pillar Two top-up taxes” guidance on 14 May 2026, confirming a pre-launch testing window for the new GloBE information return service from 13–18 May ahead of full go-live on 19 May 2026.
The UK HM Revenue & Customs (HMRC) updated its guidance on “How to report Pillar Two Top-up Taxes” on 14 May 2026, adding details of a testing period for the new information return service ahead of its launch on 19 May 2026.
HMRC said the information return service will be tested between 13 and 18 May 2026 before going live on 19 May 2026.
When to report
Once a group has registered to report Pillar Two Top-up Taxes, it must submit its UK tax return and information return on or before the deadline unless the group meets the conditions for a Below-threshold notification.
HMRC said the filing deadline is 18 months after the end of the first accounting period. From the second accounting period onwards, the submission deadline will be 15 months after the end of the accounting period.
The guidance notes that an information return, also known as a GIR or GloBE information return, is separate from the UK tax return.
HMRC also said businesses must submit their UK tax return together with either an information return or an overseas return notification by the submission due date. The Pillar Two Top-up Taxes dashboard, accessed through the business tax account, will display details of due dates and overdue returns.
What happens if report late
HMRC warned that penalties may apply if returns are not submitted by the deadline. Businesses were directed to the Multinational Top-up Tax and Domestic Top-up Tax manual for additional information.
What will need
Businesses must complete registration for Pillar Two Top-up Taxes before making submissions.
HMRC said businesses will need:
- a Pillar Two ID received on the confirmation page after registration; and
- access to third party software that offers Pillar Two services.
The guidance also advises businesses to check the accounting period carefully before submission because, once a submission has been made for an accounting period, that accounting period cannot be changed.
How to report
HMRC said businesses must use compatible software to submit Pillar Two Top-up Taxes returns. The submission service through software providers will be available from 19 May 2026.
The authority is also testing the new information return service between 13 and 18 May 2026.
Businesses volunteering for the testing phase must email pillar2mailbox@hmrc.gov.uk and confirm that they:
- are registered for Pillar Two Top-up Taxes; and
- have received confirmation from their software provider that the software has been accredited to submit information returns.
HMRC said it will then contact participating businesses with further information.
According to the guidance, if an information return is submitted successfully during the testing period, it will not need to be submitted again once the service goes live on 19 May 2026.
Below-threshold notification
HMRC said a group may submit a Below-threshold notification through the Pillar Two dashboard if the group:
- does not have consolidated annual revenues of EUR750 million or more in at least two of the previous four accounting periods; and
- is not expected to make consolidated annual revenues of EUR750 million or more within the next two accounting periods.
After submission of the return
HMRC said businesses will receive an email confirming that the information return has been received and whether it has been accepted.
If an email indicates that there were errors in the return, businesses are instructed to contact their software provider.
After reporting
HMRC confirmed that businesses successfully submitting an information return during the testing period between 13 and 18 May 2026 will not need to submit the return again after the information return service officially launches on 19 May 2026.
Earlier, UK HMRC updated their guidelines on “How to report Pillar Two Top-up Taxes” and “Register to report Pillar Two Top-up Taxes” 1 September 2025.
