Hong Kong IRD Begins Mandatory E-Filing for Profits Tax: What Companies Need to Know for 2025/26

The 2025/26 profits tax filing season marks a turning point for large businesses in Hong Kong. For the first time, the Inland Revenue Department (IRD) has mandated electronic filing for certain corporate taxpayers, kicking off a multi-year transition toward full digital tax administration.

Who Is Affected

The new mandatory e-filing requirement applies to Hong Kong entities that are part of a multinational enterprise (MNE) group with annual consolidated revenue of at least EUR 750 million in at least two of the preceding four financial years.

These entities will no longer receive paper profits tax returns. Instead, they receive a Notification to File a Profits Tax Return (Form IRC 1952/1953), either through the IRD's newly launched Business Tax Portal (BTP) or by post. All filing must be completed electronically through the BTP, unless the entity qualifies for a specific exemption — such as being in liquidation or having a financial period exceeding 12 months.

e-Filing Brings an Extra Month

One immediate benefit: companies that e-file voluntarily can apply for an additional one-month extension beyond their standard block extension deadline. For example, a company with a "D" accounting code (year-end December 2025) now has until 17 August 2026 to file via paper, or 17 September 2026 via e-filing. The extra month provides valuable breathing room for tax teams managing complex iXBRL submissions.

New iXBRL Taxonomy and Form Changes

On 1 April 2026, the IRD released the latest iXBRL taxonomy package and data preparation tools. All electronic filings must comply with the updated taxonomy specifications. Alongside this, the BIR 51 and BIR 52 return forms now require taxpayers to declare whether they fall under the mandatory e-filing regime, and to disclose any unilateral foreign tax credit claims under the Foreign-Sourced Income Exemption (FSIE) regime.

The supplementary Form S2 has also been expanded to capture information about Global Minimum Tax (GMT) and Hong Kong Minimum Top-up Tax (HKMTT) filing obligations for in-scope MNE groups — reflecting the broader Pillar Two implementation.

What's Next: 2030 Full Mandate

The IRD has signalled its intention to achieve full mandatory e-filing by 2030. The next phase, expected around 2028, will extend the requirement to businesses whose total turnover exceeds a yet-to-be-announced threshold. Companies that are not currently caught by the EUR 750 million rule should use this window to familiarise themselves with the BTP, the iXBRL taxonomy, and the digital filing workflow.

Deadline Reminder

For companies with 31 March 2026 year-ends and no tax representative ("M" code profitable cases), the profits tax return deadline is 16 November 2026, extendable to 16 December 2026 with e-filing. Early preparation is recommended.

Sources: KPMG Hong Kong Tax Alert (July 2026); IRD Electronic Filing of Profits Tax Return guidance.