If you run a Hong Kong company and haven't looked at your 2025/26 profits tax filing yet, you're probably fine — most companies fall somewhere on the Block Extension Scheme timeline. But this filing cycle is different: the IRD has flipped the switch on mandatory e-filing for a growing slice of taxpayers, and block extension applications no longer accept paper forms at all.

Here's what's changed, what your deadlines actually are, and what you need to do before the end of the year.

Who Has to E-File in 2026 (and Who Gets an Extra Month)

Mandatory e-filing started 1 April 2026, but only for a specific group: companies that belong to a multinational enterprise (MNE) group with consolidated revenue of EUR 750 million or more in at least two of the past four years. If that's you, the IRD already issued your Notice to File (Form IRC1952) through the Business Tax Portal instead of mailing a paper BIR51. You must submit the return, financial statements in iXBRL format, and the tax computation all digitally.

The EUR 750 million threshold might sound like it only applies to giants — and for now, that's mostly true. But the IRD's roadmap phases e-filing out to more company types every year. Newly incorporated companies are next in line. If you set up a Hong Kong company in 2025 or later, expect your first profits tax return to be digital-only. Smaller existing companies will follow in later phases.

Here's the catch that even accountants sometimes miss: if you voluntarily e-file and submit iXBRL financials, you get an extra month beyond your standard block extension deadline. Mandatory e-filers get this automatically. Voluntary filers have to apply for it. For a D-code company (December year-end), that moves the deadline from 31 August to 2 October 2026 — a meaningful chunk of extra time.

Your Real 2026 Filing Deadline (Not Just the One-Month Standard)

The IRD issued 2025/26 Profits Tax Returns on 1 April 2026. The standard deadline is one month from issue — 4 May 2026 — but almost no established company files by then. The Block Extension Scheme (BES) gives tax representatives much longer windows based on your accounting year-end code.

Let's be direct: if you're reading this in September and you haven't filed yet, you're almost certainly on an extension. The question is which one.

• N Code (year-end between 1 April and 30 November 2025): Deadline was 4 May 2026. Eligible e-filers got until 4 June 2026. This group is done for the year.
• D Code (31 December 2025 year-end): Standard BES deadline is 31 August 2026. E-filing pushes it to 2 October 2026. If your accounts are still in draft, you're cutting it close.
• M Code — profit cases (year-end 1 January to 31 March 2026): Deadline 16 November 2026. E-filing extends to 16 December 2026.
• M Code — loss cases: Deadline 1 February 2027. No further e-filing extension applies.

Paper-based block extension applications are gone. Your tax representative must submit the BES application through the Tax Representative Portal (TRP). If your current tax firm is still working with paper forms, that's a red flag.

Provisional Tax — Why First-Time Filers Get Sticker Shock

When your first profits tax assessment arrives, you'll see two numbers: final tax for 2025/26, and provisional tax for 2026/27. They're due together.

Provisional tax isn't a penalty. It's just the IRD collecting next year's estimated tax in advance, based on this year's profits. For a company with a December year-end, the first instalment (about 75% of the estimated amount) lands with your final tax bill, usually in November. The remaining 25% follows about three months later, in January.

New companies often underestimate how much cash to set aside because they only budget for the first year's tax. Plan for roughly double in your second year of operation to cover both the final and provisional amounts.

If you genuinely expect profits to drop by more than 10% next year, you can apply to hold over some or all of the provisional tax. The IRD won't take your word for it — you'll need management accounts or other documentary support. Applications must arrive at least 28 days before the payment due date, or 14 days after the assessment notice, whichever is later.

What Happens if You Miss the Deadline

Filing and payment are assessed separately, and both hurt if you're late.

Late filing starts with a fixed HK$1,200 penalty for a first offence. Repeat or prolonged non-compliance can push that up to HK$10,000, plus additional tax of up to three times the amount undercharged in serious cases. If you simply ignore the return, the IRD will raise an estimated assessment based on your prior year's profits — and you'll pay that amount on top of any surcharge, while you fight to get it revised.

Late payment gets expensive fast. A 5% surcharge kicks in immediately after the due date. Six months later, another 10% is added on top. Interest also accrues daily from the due date to the date you actually pay.

Common mistake: thinking you can ignore a profits tax return because the company made a loss. Loss-making companies still must file. Dormant companies are the only exception, and even then only if they're formally dormant under the Companies Ordinance.

How to Get Ready If You're Not There Yet

If your filing deadline is still a few months out (M-code companies, we're looking at you), here's what to do now instead of waiting until October:

• Confirm your accounting date code with your tax representative. If you've changed your financial year-end, your code may have shifted from what you used last year.
• Start the audit now, not in November. Auditors are busiest in Q4, and rush jobs cost more.
• Digitise your records. Even if e-filing isn't mandatory for you yet, it will be soon. If your accounting system is still spreadsheet-based, 2026 is the year to move to a proper cloud accounting platform that can export in IRD-compatible formats.
• Budget for provisional tax. Set aside roughly the same amount as your 2025/26 final liability so the combined bill doesn't catch you off guard.
• Check whether your group hits the EUR 750M threshold. If you're part of a multinational structure and you're not sure, find out now — the filing method and extension rules are different.

The shift to e-filing isn't coming — it's here, and it's expanding every year. Companies that get their systems and processes in place now will have an easier time as the IRD rolls out mandatory digital filing to the rest of the market.

Need help with your 2025/26 profits tax filing, e-filing setup, or block extension application? Email us at info@lcpa.com.cn or call +852-55749538. Lemon Accountancy handles Hong Kong audit, tax computation, and IRD filings for companies of all sizes.

Disclaimer: This article provides general information only and does not constitute tax advice. Tax obligations depend on your specific circumstances. Consult a qualified tax professional for advice tailored to your situation.