A reference, not advice. Deadlines, forms and channels change — several did during
the first cycle, some within weeks of their own due date. Verify against the tax
authority’s current guidance before you rely on anything here. Dates shown are for a
group first in scope for a fiscal year ending 31 December 2024.
United Kingdom
First return 18 months after year end; 15 months thereafter.
- Domestic top-up tax
- Domestic Top-up Tax (DTT), alongside Multinational Top-up Tax (MTT)
- Information return
- GloBE Information Return (GIR)
- If filed elsewhere
- Overseas Return Notification (ORN)
- Also required
- UK self-assessment return, even where no top-up tax is due
- Channel
- HMRC Pillar 2 service; GIR by file transfer, ORN via compatible software
Watch: the transitional relief from local GIR filing depends on the ORN reaching HMRC on time. Submitting the ORN is the condition entirely within your control, and the one most often skipped. The self-assessment return survives the ORN — filing one does not remove the other.
Ireland
First return 18 months after year end; 15 months thereafter.
- Domestic top-up tax
- Qualified Domestic Top-up Tax (QDTT)
- Information return
- Top-up Tax Information Return (TIR)
- If filed elsewhere
- Notification of Filer (NoF)
- Registration
- Within 12 months of the first in-scope fiscal year, via ROS
- Channel
- Revenue Online Service (ROS)
Watch: registration carries a €10,000 penalty for failure, and TIR registration is required even for entities that will never file one. By the first deadline Revenue had received just over 40 TIRs against around 700 Notifications of Filer and more than 600 domestic returns — roughly one group in fifteen filed the information return locally.
Australia
First lodgment 18 months after year end; 15 months thereafter.
- Domestic top-up tax
- Domestic Minimum Tax (DMT), reported in the DMTR
- Information return
- GloBE Information Return (GIR), lodged separately
- If filed elsewhere
- Foreign lodgment notification, inside Section 3 of the CGDMTR
- Also required
- AIUTR and DMTR, combined with the notification into the CGDMTR
- Channel
- Online services file transfer, or API-enabled software
Watch: the automatic 30-day deferral covers the AIUTR and DMTR only — neither the GIR nor the foreign lodgment notification can formally be deferred. A designated local entity lodging for more than 20 Australian entities cannot use the portal at all and must use the API channel.
Netherlands
Information return and notification 15 months after year end, 18 in the transitional year. Local return and payment 17 months, 20 in the transitional year.
- Domestic top-up tax
- Local top-up tax return, covering IIR, UTPR and QDMTT in one form
- Information return
- Bijheffing-informatieaangifte (BIA), the Dutch GIR
- If filed elsewhere
- Kennisgeving (notification)
- Channel
- Three separate channels: Digipoort for the BIA, the Gegevensportaal for the notification, Mijn Belastingdienst Zakelijk for the return
Watch: three obligations through three different portals, each needing its own access. The information return and the local return sit two months apart, so a single project plan built around one date will miss the other.
Belgium
QDMTT return 11 months after year end under domestic law. First-year QDMTT and IIR returns were extended twice, to 30 September 2026. The GIR deadline did not move.
- Domestic top-up tax
- QDMTT return
- Information return
- GloBE Information Return (GIR)
- If filed elsewhere
- GIR notification
- Also required
- Separate IIR return
Watch: the 11-month clock puts the QDMTT return ahead of the GIR, not behind it — a group planning backwards from the GIR date finds a Belgian return that was due first. Extensions are granted per return type, not per jurisdiction: the QDMTT and IIR moved while the GIR and its notification stayed at 30 June.
Germany
GIR 18 months after year end, 15 months thereafter. Group head notification within two months of the end of the tax period.
- Domestic top-up tax
- Minimum tax return (Mindeststeuer), filed with the competent state tax office
- Information return
- GIR (Mindeststeuer-Bericht), filed with the Federal Central Tax Office
- If filed elsewhere
- Group head notification
- Channel
- BZSt, in XML — via the DIP mass-data interface or the portal’s XML upload form
Watch: three obligations split across two authorities, and the notification runs on a two-month clock against an 18-month GIR window. The DIP interface requires technical setup, and portal access runs on an ELSTER certificate, a BZSt certificate or the federal user account — simple credentials are not always sufficient. Late or incomplete GIR submission, where intentional or reckless, carries up to €30,000.
No jurisdiction selected.