Hong Kong's 2025/26 Profits Tax filing cycle introduces mandatory electronic filing for qualifying multinational groups, updated iXBRL reporting requirements and revised filing arrangements.
From 1 April 2026, affected businesses must submit their returns electronically, while other companies can continue to use paper filing or opt for e-filing.
This guide explains who must comply, the applicable deadlines, key regulatory changes and the steps businesses should take to prepare.
Who Must Comply with the New E-Filing Rules in 2026?
Mandatory e-filing applies to qualifying Hong Kong entities of multinational groups with annual consolidated revenue of at least €750 million in two of the four preceding fiscal years, where the relevant group financial year begins on or after 1 January 2025.
| Entity Category | E-Filing Requirement |
|---|---|
| Hong Kong constituent entities | Mandatory if the group meets the revenue threshold. |
| Qualifying joint ventures | Mandatory where the relevant ownership and accounting conditions are met. |
| Existing mandatory e-filers | Must generally continue e-filing, even if circumstances change, subject to limited exceptions. |
| Other businesses | Paper or voluntary e-filing permitted. |
The new requirement applies from the 2025/26 year of assessment. Businesses should review each Hong Kong entity separately rather than assume that every group company has identical filing obligations.
What Has Changed in Hong Kong's Profits Tax Filing Process?
The 2026 changes affect how businesses receive tax notices, prepare supporting documents and disclose tax information.
| Key Change | What Businesses Need to Know |
|---|---|
| Electronic filing | File through the Business Tax Portal (BTP), or through the Tax Representative Portal (TRP) using an authorised representative. |
| iXBRL reporting | Electronic filers generally need to submit financial statements and tax computations in iXBRL format, unless exempt. |
| Updated tax returns | Revised BIR51 and BIR52 forms include mandatory e-filing declarations. |
| Additional disclosures | Relevant businesses must review foreign tax credit and global minimum tax reporting requirements. |
| Supplementary forms | Submit applicable forms electronically in XML format, even when filing the main return on paper. |
The IRD introduced updated iXBRL preparation tools and taxonomy packages on 1 April 2026. Businesses should use the current versions and resolve validation errors before submitting their returns.
What Are the 2026 Profits Tax Filing Deadlines and Extensions?
Hong Kong's Profits Tax filing deadlines depend on your accounting year-end, filing method and eligibility for the IRD's Block Extension Scheme (BES).
The following deadlines apply to qualifying 2025/26 cases handled by tax representatives.
| Accounting Year-End | Paper Filing | Eligible E-Filing |
|---|---|---|
| N-code: 1 Apr–30 Nov 2025 | 4 May 2026 | 4 June 2026 |
| D-code: 1–31 Dec 2025 | 31 August 2026 | 2 October 2026 |
| M-code: 1 Jan–31 Mar 2026 | 16 November 2026 | 16 December 2026 |
| M-code: qualifying loss cases | 1 February 2027 | 1 February 2027 |
The D-code dates reflect the IRD's July 2026 extension. The e-filing dates are subject to the applicable eligibility and extension conditions.
Who Qualifies for an Extension?
- Block Extension Scheme (BES): Businesses appointing a tax representative may qualify for extended deadlines based on their accounting year-end.
- Voluntary e-filing: Eligible businesses choosing electronic filing can apply for the extended e-filing dates shown above.
- Mandatory e-filing: Qualifying businesses that notified the IRD before March 2026 generally receive the additional extension automatically.
- M-code loss cases: Tax representatives must apply by 2 November 2026 for the 1 February 2027 deadline. No further extension applies.
| Upcoming Deadlines |
|---|
| As at 24 September 2026, the next key deadline is 2 October for eligible D-code e-filers, followed by the M-code deadlines in November and December. Businesses should confirm their approved extensions before relying on these dates. |
How Should Businesses Prepare for the 2026 Filing Requirements?
Five practical steps can help businesses prepare their 2025/26 Profits Tax Returns and avoid filing delays.
- Confirm your filing obligations. Check whether mandatory e-filing applies, identify your accounting year-end code and verify your deadline.
- Check portal access. Activate your BTP or TRP account, monitor electronic notices and confirm signing authorisation.
- Prepare supporting documents. Finalise audited accounts, tax computations and applicable supplementary forms.
- Validate electronic files. Prepare the required iXBRL and XML files using the latest IRD tools. Resolve validation errors before filing.
- Complete and retain your filing records. Submit the signed return with its supporting documents and retain the IRD acknowledgement.
How Ascentium Hong Kong Can Help
Our Hong Kong tax and accounting teams can help you determine your filing obligations, prepare tax computations, coordinate with external auditors and manage Profits Tax filings and IRD correspondence.
For multinational groups, we also provide tax advisory support to help address cross-border reporting requirements and manage compliance across entities.
