Common Profits Tax Filing Mistakes for March Year-End Companies in Hong Kong, Ahead of the 30 November Paper Filing Deadline

For Hong Kong companies with a 31 March year-end, the 2025/26 Profits Tax Return deadline is extended to 30 November 2026. The mistakes that cause trouble at this stage are often about process rather than the numbers: assuming an extension applies when it does not, filing in the wrong mode, or leaving out a form that has to go in with the return.

This guide starts with the date itself, because 30 November is narrower than it sounds, and then sets out the six mistakes that most often cost March year-end filers time or penalties. For the wider background on who must file and how provisional tax works, see our profits tax filing guide for 2026.

See also: Hong Kong Profits Tax Filing Guide 2026: Deadlines, Requirements and Preparation

Who does the 30 November deadline actually apply to?

The date comes from the Inland Revenue Department’s (IRD) Block Extension Scheme (BES), which lets tax representatives obtain extended due dates for their clients. For 2025/26, the dates are as follows.

Three points follow. M-code covers every year-end between 1 January and 31 March, not only 31 March. 30 November is the extended deadline for companies that use a tax representative, so a company without one generally faces the standard deadline of one month from issue, which for 2025/26 was 4 May 2026. The later dates in the table depend on conditions, as explained in the first mistake below.

What are the most common profits tax filing mistakes for March year-end companies?

1. Assuming the extensions are automatic.

The block extension depends on a tax representative having acted through the Tax Representative Portal, and a company that appointed an adviser late should confirm in writing that it is covered. The other extensions carry their conditions:

• E-filing extension to 30 December. Mandatory e-filers receive it without application if the IRD was notified of their status before March 2026. [QZ1] Voluntary e-filers must apply, and the application must reach the IRD at least seven working days before the due date.
• Loss-case extension to 1 February 2027. The representative’s list of loss cases was due by 2 November 2026, with individual requests accepted up to the applicable filing deadline, and the return must show an allowable loss. If a company obtains the loss extension and then reports assessable profits, or obtains the e-filing extension and then files on paper, the extension is void from the start and the IRD may consider penalties under section 80 or 82A of the Inland Revenue Ordinance.
• Further extensions. Beyond the block dates, these are granted only in exceptional circumstances, on written request with evidence at least 14 days before expiry. For 30 November that window has effectively closed, so the realistic plan is to be ready to file.

2. Filing on paper when e-filing is mandatory.

From the 2025/26 year of assessment, Hong Kong entities in multinational groups with consolidated revenue of EUR 750 million or more in at least two of the previous four years must e-file. This includes entities that previously had no annual filing obligation, and the IRD issues no paper return to them. Paper filing without an approved exception is not permitted. The 2025/26 return also has new checkboxes (items 3.9 and 3.9.1 on the BIR51) identifying these entities. Check the Business Tax Portal for notices, because they may arrive there rather than by post.

3. Treating supplementary forms as a separate step.

Forms such as S5 to S15 must be filed at the same time as the return and have the same due date. They cannot be filed separately or later. For the years of assessment 2020/21 to 2026/27, they must be submitted electronically through the Business Tax Portal or the Tax Representative Portal, even where the return itself is on paper, by exporting the completed form to XML and uploading it. A paper return filed without its electronic supplementary forms is not a complete filing.

4. Getting the two-tiered rate election wrong.

The 8.25% rate on the first HK$2 million of profits is available to only one entity in a group of connected entities. Entities are connected where one controls the other, or both are controlled by the same entity, and control is broadly determined under the connected-entity rules and may arise through ownership, voting power or entitlement to income and capital. The election is made in the return and cannot be revoked for that year. If no entity validly elects, all assessable profits are taxed at 16.5%. Incorrectly declaring that there is no connected entity, or that none has elected, can lead to assessment adjustments, additional tax and penalties.

5. Submitting accounts that do not meet IRD requirements.

• Photocopies of returns and uncertified financial statements are not accepted.
• Audited accounts are generally required, even for loss-making companies. The exemption for dormant companies depends on the company having completed the relevant statutory procedure.
• Foreign-currency figures should be translated consistently with the company’s accounting records and applicable accounting standards.
• For 2025/26, taxpayers preparing accounts under IFRS or HKICPA standards must use those accounts for the profits tax computation.

6. Making offshore or foreign-sourced income claims without evidence.

Claims that profits are offshore or that foreign-sourced income falls outside the foreign-sourced income exemption (FSIE) regime need documentary support. The IRD is looking closely at economic substance, participation conditions and claims that income was “not received in Hong Kong”. The 2025/26 return has a new item (10.20) for the unilateral foreign tax credit claimed under the FSIE regime. For in-scope multinational groups, the new Section 4 of Form S2 asks for global minimum tax filing information, but completing it does not replace the separate top-up tax notice.

What happens if a March year-end company gets it wrong?

Returns not lodged by the extended due date may lead to estimated assessments or penalty proceedings, and persistent late filers are very likely to be penalised. The IRD’s published penalty policy sets out the range of outcomes:

• Prosecution under section 80(2) for late or incorrect returns carries a fine of HK$10,000 plus up to three times the tax undercharged.
• Additional tax under section 82A is an alternative to prosecution, capped at three times the tax undercharged.
• Typical profits tax penalties for late filing start at around 10% of the tax undercharged for a first offence, 20% for a second within five years and 35% for a third or later offence. The rates rise to 20%, 30% and 50% where the return is filed only after two or more estimated assessments.

The IRD also encourages voluntary disclosure, and prompt, full disclosure may be treated more favourably.

How should March year-end companies use the weeks before 30 November?

1. Confirm the deadline and filing mode: Check that a tax representative is appointed and the company is listed under the BES, whether the company is a mandatory e-filer, and whether any e-filing extension was actually obtained before relying on 30 December.
2. Settle the accounts: Make sure the audited financial statements are signed, certified, and consistent with the tax computation.
3. List every supplementary form: Prepare each as XML for electronic upload, and plan to file them with the return.
4. Review elections and claims: Check the two-tiered rate declaration across the group, and assemble evidence for any offshore, FSIE or “not received in Hong Kong” position.
5. For loss-making companies, confirm the extension: Check that the company is on the representative’s loss-case list and that the return will show an allowable loss.
6. Check portal access and signing authority: Confirm who monitors the Business Tax Portal and that iXBRL tools are updated to the 2026 taxonomy. If a liquidator has been appointed, only the liquidator may sign the return. Where a service provider files for the company, Form IR1476 must be signed by the company and kept available for production.
7. Keep records of what was filed: Retain acknowledgements and supporting papers.

Key takeaway

The substance of a profits tax return rarely changes much from year to year. What changes is the process around it: which mode is mandatory, which extension applies and which forms must travel with the return. March year-end companies that confirm those points now, rather than in the final days before 30 November, give themselves the best chance of filing a complete, correct return without penalty.

Frequently asked questions (FAQs)

When is the profits tax return due for a March-year-end company?

For companies using a tax representative under the Block Extension Scheme, the 2025/26 return is due on 30 November 2026 for M-code companies (year-ends between 1 January and 31 March 2026). Companies without a tax representative generally faced the standard one-month deadline, which for 2025/26 was 4 May 2026.

Can a March year-end company get more time after 30 November?

Possibly. E-filers can obtain an additional month, to 30 December, but voluntary e-filers must apply at least seven working days before the due date. Loss-making companies can extend to 1 February 2027 if their representative included them on the loss-case list. Other further extensions are granted only in exceptional circumstances and on written request.

Do loss-making companies still need to file a profits tax return?

Yes. A loss does not remove the filing obligation. Audited accounts and a tax computation are generally required, except for companies that are formally dormant.

Can we file on paper for 2025/26?

It depends on the entity. Hong Kong entities in multinational groups with consolidated revenue of EUR 750 million or more in at least two of the previous four years must e-file, unless an exception is approved. Other companies can still file on paper, but they must submit supplementary forms electronically.

Do supplementary forms have a separate deadline?

No. They must be filed with the return and have the same due date. They cannot be filed separately or later.

What is the penalty for filing late?

The IRD may issue estimated assessments, assess additional tax, or prosecute. Under its published penalty policy, typical profits tax penalties for late filing start at about 10% of the tax undercharged for a first offence, with higher rates for repeat offences. Statutory maximums are considerably higher.

How Dezan Shira & Associates can help

A profits tax return is judged on its process as much as its numbers: the right deadline, the right filing mode, and the right supporting forms and evidence for every claim. Dezan Shira‘s tax advisors help companies confirm their filing position, prepare and review the return and supporting documentation, and resolve queries from the IRD. Contact our local team for tailored support.