- A profits tax return (PTR) is the annual return you file with the IRD to report assessable profits. Corporations use Form BIR51.
- File within one month of the issue date unless you have a tax representative under the block extension scheme (N / D / M codes by financial year-end).
- Submit the return with audited financial statements and a tax computation when the company had gross income in the basis period.
- Your first PTR usually arrives about 18 months after incorporation, with about three months to file from issue.
- Late or incorrect filing can mean a fine of up to HK$10,000, up to three times the tax undercharged, an estimated assessment, or a compound penalty offer.
A profits tax return (PTR) is the annual return a business files with the Hong Kong Inland Revenue Department to report assessable profits. Corporations file Form BIR51, usually with audited financial statements and a tax computation.
- Deadline: generally 1 month from the IRD issue date; represented cases get block-extension dates by year-end code (N / D / M)
- First return: usually issued about 18 months after incorporation; typically due within 3 months of issue
- E-file: Business Tax Portal (BTP) or Tax Representative Portal (TRP); all applicable supplementary forms must be filed electronically
- Late: up to HK$10,000 + up to 3× tax undercharged; estimated assessment risk
Profits tax return Hong Kong filing means completing Form BIR51 (for corporations), usually with audited accounts and a tax computation, within one month of the IRD issue date unless a tax representative has secured a block extension.
Miss the window and you can face a fine of up to HK$10,000, up to three times the tax undercharged, or an estimated assessment.
In this guide, you’ll learn:
- What Form BIR51 is, and when BIR52 or BIR54 applies
- Who must file and the normal filing window
- How to file step by step (records → audit → computation → BIR51 → submit)
- What to submit with the return, and how e-filing works on BTP / TRP
- When your first PTR arrives
- Deadlines, nil/offshore/loss pointers, and late-filing consequences
What is a profits tax return (BIR51)?
A profits tax return is the IRD form used to report your assessable profits (or adjusted loss) for a year of assessment. For corporations, that form is BIR51 (“Profits Tax Return – Corporations”).
The IRD uses the return, plus your accounts and tax computation, to assess profits tax. Corporations currently pay 8.25% on the first HK$2 million of assessable profits and 16.5% above that under the two-tiered profits tax rates. For how book profit becomes assessable profit, see taxable income for Hong Kong companies.
If the IRD issues a BIR51, you must file it. Silence is what escalates cases.
What are the profits tax return forms: BIR51, BIR52, BIR54?
Hong Kong uses different PTR forms by entity type.
Form | Who files it | Typical attachments |
|---|---|---|
Corporations (Hong Kong companies and foreign companies with a Hong Kong presence) | Audited financial statements + tax computation (when required) | |
Persons other than corporations: sole proprietors and partnerships | Financial statements + tax computation (audit rules differ) | |
Non-resident persons with Hong Kong-sourced income and no local permanent establishment | As specified in the Notes and Instructions |
Most Hong Kong limited companies file BIR51. Supplementary forms (S1 to S22, where applicable) report preferential regimes and incentives. Those must be filed electronically via the Business Tax Portal or Tax Representative Portal, even if the main return goes in on paper (IRD e-filing guidance).
Who has to file a profits tax return, and when?
If the Inland Revenue Department (IRD) issues your business a Profits Tax Return, you must file it by the deadline shown on the form.
This applies even if your company:
- Made no profit
- Had no business activity
- Is formally dormant, unless the IRD has stopped issuing returns to it
Standard deadline
You normally have one month from the issue date shown on the return to file it.
For established companies
For most established businesses, the IRD usually issues profits tax returns on the first working day of April for the relevant year of assessment.
If you appoint a tax representative, you may qualify for extra time under the block extension scheme. Your extended deadline depends on your company’s financial year-end and its N, D, or M code. See profits tax deadlines and block extension for the current dates.
No return does not always mean no obligation. If your company has chargeable profits but has not received a return, notify the IRD and request one rather than waiting for a form to arrive.
How do I file my profits tax return, step by step?
For most Hong Kong companies, the filing order is simple: check the notice, prepare the records, finalise the audit, calculate tax, complete BIR51, and submit it on time.
If an accountant files for you, you still need to provide complete records and arrange for an authorised person to sign the return.
Before you start
You will normally need:
- The IRD profits tax return notice
- Complete accounting records for the relevant period
- Audited financial statements
- A profits tax computation
- An authorised signer, such as a director, company secretary, or manager
Important: Uploading documents is not the same as filing. The signed BIR51 must still be submitted by the due date.
Step 1: Check the IRD notice
When the green return form arrives—or when you open it in the Business Tax Portal—check the details immediately.
Write down:
- Form type: usually BIR51 for a limited company
- Year of assessment, such as 2025/26
- Profits Tax File Number
- Return Identification Number (RIN)
- Issue date and filing deadline
- Whether the IRD has a tax representative recorded for your company
Add the filing deadline to your calendar on the same day. The standard filing window is usually one month from the issue date, unless an extension applies.
Your accounts may end on 31 December, 31 March, or another financial year-end. That accounting period is separate from the profits tax year of assessment, which runs from 1 April to 31 March.
First return? New companies usually receive their first BIR51 around 18 months after incorporation and typically have around three months to file. Do not assume the usual April bulk-extension timetable applies unless your tax representative confirms it.
Step 2: Gather your records
Create one complete records pack for the accounting period shown on the return. This gives your accountant and auditor what they need to prepare the accounts and tax computation.
Include:
- Bank statements and reconciliations for every company account
- Sales invoices, contracts, and proof of payment
- Supplier invoices, expense claims, and business credit-card, FPS, or PayMe records
- Payroll summaries, MPF records, and director-fee resolutions
- Fixed-asset register, including purchases, disposals, and written-down values
- Loan agreements, interest schedules, and related-party invoices
- Prior-year tax computation and IRD assessment, if available
Keep business records for at least seven years. Missing bank records, unsupported expenses, and undocumented director drawings are common causes of delays.
Step 3: Finalise the books and audit
Most Hong Kong companies need audited financial statements before filing their profits tax return.
Your filing package will generally include:
- Statement of financial position, or balance sheet
- Statement of comprehensive income, or profit and loss account
- Auditor’s report signed by a Hong Kong CPA, where required
Engage your auditor early enough for the signed accounts to be ready before the BIR51 deadline. A formally dormant company under the Companies Ordinance is the main situation where the IRD may accept a return without audited accounts.
Founder checkpoint: Review the final audited figures before signing BIR51. The return, tax computation, and audited accounts should reconcile.
Step 4: Prepare the profits tax computation
Your accountant should prepare a profits tax computation and supporting schedules. It starts with the company’s accounting profit before tax, then adjusts it to arrive at assessable profits or an adjusted loss.
Common schedules cover:
- Add-backs, such as non-deductible expenses
- Deductions and allowable expenses
- Depreciation and capital allowances
- Losses brought forward from earlier years
- Final assessable profits or adjusted loss in Hong Kong dollars
You do not need to prepare the calculation alone, but you should understand the final assessable-profits figure before authorising the return.
Step 5: Check for supplementary forms
Supplementary forms, numbered S1 to S22, are used for specific tax regimes, incentives, and disclosures. If one applies, it must generally be submitted electronically in XML format through the Business Tax Portal (BTP) or Tax Representative Portal (TRP).
Many straightforward trading and service businesses will not need a supplementary form. Ask your accountant to confirm whether your company has a reporting obligation—for example, for certain foreign-sourced income disclosures.
If you are filing BIR51 on paper but submit a supplementary form electronically, also print, sign, and attach Control List IR1477. The same authorised person should sign both IR1477 and BIR51.
Step 6: Choose paper or electronic filing
You can file BIR51 on paper or electronically.
Paper filing
- Complete the printed BIR51
- Attach the required documents
- Obtain an authorised signature
- Post or deliver the return to the IRD by the due date
Electronic filing
You can file through the Business Tax Portal yourself, or appoint an accountant or service provider to file through the Tax Representative Portal.
If your company files through the BTP, you will generally need:
- A BTP Business Account, or limited RIN access for eligible upload-only tasks
- A BTP Administrator or authorised user with Profits Tax Matters rights
- An authorised signer: a director, company secretary, or manager
- A valid signing method, such as an Individual Tax Portal account, recognised personal digital certificate, or iAM Smart digital signing
If an accounting firm files through the TRP, it may ask you to sign IR1476, confirming its appointment as service provider.
Step 7: Complete BIR51 carefully
Complete the return with the IRD Notes and Instructions open. Before signing, check that the key details match your records.
Confirm that:
- Company name, Business Registration Number, and tax file number match the notice
- Basis period and accounting date match the audited accounts
- Turnover and profit figures reconcile to the accounts
- Assessable profits or adjusted loss match the tax computation exactly
- Offshore claims, loss claims, and connected-entity disclosures match your accountant’s work
- Contact details are current for any IRD follow-up
Do not leave required fields blank. Enter “Nil” or “0” where applicable.
Step 8: Attach or upload the supporting documents
If the company earned gross income during the basis period, the supporting package usually includes:
- Certified financial statements, including the auditor’s report where required
- Profits tax computation and supporting schedules
- Any additional documents specified in the Notes and Instructions
- Supplementary-form XML files, where applicable
- IR1477, if required for a paper return
Typical e-filing order
- Upload supplementary-form XML files, if required
- Upload the financial statements and tax computation in iXBRL, unless an IRD exception applies
- Include the auditor’s report within the financial-statements file
- Wait for validation and correct any errors
- Complete BIR51 in the Completion Service
- Sign and submit through the Submission Service, or use semi-electronic filing if a wet-ink signature is required
Most founders will not create iXBRL files themselves. Your accountant or filing software normally converts the signed accounts and tax computation; your role is to review the figures and arrange the authorised signature.
Step 9: Sign, submit, and retain proof
The final step depends on your filing method.
- Paper filing: Sign the return in wet ink and keep a full copy of the signed package.
- Full e-filing: Complete the electronic signature and save the acknowledgement.
- Semi-electronic filing: Print the system-generated return, note the Transaction Reference Number, sign it, and deliver the latest printed version to the IRD.
After submission, watch for the IRD notice of assessment. It sets out any profits tax payable and may include provisional tax for the following year.
Final reminder: The payment deadline and the filing deadline are different dates. Add both to your calendar.
Start the audit before the BIR51 lands. Bulk returns usually issue in early April. Teams that close books in March file inside the window; teams that start when the envelope arrives spend the month chasing auditor signatures and schedules.
What do I submit with the profits tax return?
If the corporation had gross income in the basis period, supporting documents go in with the return:
- Certified financial statements for the basis period, including an auditor’s report where Hong Kong or foreign law requires one (or where one has otherwise been prepared)
- A tax computation with supporting schedules showing how assessable profits or adjusted loss were calculated
- Other documents named in the Notes and Instructions (and any applicable supplementary forms, filed electronically)
Audited statements are expected for corporations except:
- Companies formally dormant under Cap. 622
- Companies incorporated where local law doesn’t require an audit and no auditor’s report was prepared
- Certain Hong Kong branches of foreign companies that supply the IRD’s specified branch information instead
No gross income in the basis period doesn’t mean “ignore the return.” If a BIR51 was issued, file it. A nil or loss position still needs a completed return.
How do I e-file a profits tax return?
You can file your company’s Profits Tax Return (BIR51) electronically through:
- the Business Tax Portal (BTP), if your company files directly, or
- the Tax Representative Portal (TRP), if an accountant or service provider files on your behalf.
The process follows the same Upload → Complete → Submit sequence as described in Steps 6 to 9, but within the electronic services rather than by paper.
Who can sign an e-filed BIR51?
An authorised person must sign the return. This can be:
- a director,
- a company secretary, or
- a manager of the company,
or an engaged service provider where a signed IR1476 has been submitted.
The signer can authenticate using:
- an Individual Tax Portal account,
- a recognised personal digital certificate, or
- iAM Smart with digital signing enabled.
Common e-filing pitfalls
These issues often cause validation failures or file delays:
- Uploading files but not submitting: Completing the Upload Service alone does not file your return. You must also complete the Submission Service.
- Mismatch between computation and return: The assessable profits or adjusted loss in your iXBRL tax computation must match the figure entered in the Completion Service.
- Missing auditor’s report: The signed auditor’s report must be embedded in the financial-statements iXBRL file. Without it, validation may fail.
- Outdated supplementary-form package: If you replace or re-upload supplementary forms, you must also re-print and sign a fresh IR1477 where required (paper BIR51 scenarios).
- Using an obsolete semi-electronic print: Only the latest system-generated print with the correct Transaction Reference Number can be accepted for wet-ink signature.
Additional points to note
- All supplementary forms (S1 to S22) must be e-filed electronically, even if the main BIR51 is submitted on paper.
- Represented taxpayers who e-file may receive an additional one-month extension on top of the block-extension deadline, where the current rules allow it. Whether this is automatic or must be requested depends on the latest IRD circular.
When do I get my first profits tax return?
The Inland Revenue Department (IRD) usually issues a new company’s first Profits Tax Return (BIR51) around 18 months after incorporation.
You will typically have about three months from the issue date to file it. This first return often falls outside the usual April bulk-issue timetable and its N, D, and M filing extensions.
What to prepare beforehand
Your first accounting period can last up to 18 months, depending on the financial year-end your directors choose. Start the audit early so your audited accounts and tax computation are ready when the BIR51 arrives.
What happens after the first return?
After the first filing, most companies move into the IRD’s usual April bulk-issue cycle. If you appoint a tax representative, your filing deadline may then follow the relevant N, D, or M extension category.
What are the profits tax deadlines and the block-extension scheme?
Default deadline is one month from the issue date on the return.
With a tax representative, the IRD’s block extension scheme groups bulk returns by accounting date code:
|
Code |
Financial year-end falls in |
Typical extension pattern |
|---|---|---|
|
N |
April to November |
Shortest runway (often early May) |
|
D |
December |
Mid-year extension (typically August) |
|
M |
January to March |
Longest extension (typically November; loss cases can go later) |
Exact dates are set each year in the IRD circular. Current year-of-assessment dates are in profits tax deadlines and block extension.
What if my return is nil, offshore, or a loss?
File the BIR51 if it was issued. The label on the outcome changes; the duty to file doesn’t.
- Nil / no assessable profits: complete the return for the year. Dormant status under Cap. 622 can change the accounts attachment rules, but it doesn’t automatically cancel a return the IRD has already issued.
- Offshore profits claim: still file; the claim and evidence sit inside the return package.
- Adjusted loss: file the return showing the loss. Losses generally carry forward to offset future assessable profits; see taxable income for Hong Kong companies for how the loss is computed.
Expense categories that reduce assessable profits are listed in profit tax deductible expenses.
What happens if I file late or don’t file?
Late or missing filing is an offence under the Inland Revenue Ordinance.
In practice you can face:
- A fine of up to HK$10,000, and for incorrect returns without reasonable excuse a further fine of up to three times the tax undercharged
- An estimated assessment based on the IRD’s own figures
- A compound penalty offer to settle instead of prosecution
- Escalation toward summons or prosecution if you ignore reminders
Paying tax late is separate: a 5% surcharge, with a further 10% on amounts still unpaid after six months. See business penalties in Hong Kong for the full escalation ladder.
An unanswered BIR51 is more expensive than a late but complete one. File the outstanding return as soon as you can, even after the due date, then deal with any compound offer or estimated assessment in writing before its response deadline.
How Sleek files your profits tax return
The PTR is the centrepiece of Hong Kong tax compliance. Sleek runs it as the end of the accounts and audit cycle, not a last-minute scramble.
With Sleek, you can:
- Have the full package prepared: our accounting and tax team finalises the accounts, builds the tax computation, and completes BIR51.
- File inside the right window: we track your year-end code, block-extension date, and any e-filing extension so the return goes in on time.
- Handle first returns cleanly: for new companies, we plan the first audit against the ~18-month IRD issue so you’re ready when BIR51 arrives.
- Respond if something goes wrong: late notices, compound offers, and estimated assessments get a filing-first response, then a written reply.
For the wider map of what Hong Kong taxes and what it doesn’t, see Hong Kong’s tax system.
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FAQs about filing profits tax returns in Hong Kong
A director, the company secretary, a manager, or another authorised person named in the Notes and Instructions can sign. The same person must sign Control List IR1477 if you uploaded supplementary forms electronically but are filing the main return on paper. Mismatched signatures are a common reason paper packs bounce back.
No. Sole proprietors and partnerships generally file BIR52. Corporations file BIR51. Non-residents with Hong Kong-sourced income and no local permanent establishment typically use BIR54.
It’s the unique ID printed on the profits tax return for that year of assessment. You need it for e-filing uploads and to link supplementary-form XML files to the correct return in BTP or TRP. Keep the notice with the RIN until the return is acknowledged.
No. E-filing changes how you submit documents, not whether corporations need audited financial statements. Most Hong Kong companies still attach audited accounts and a tax computation when they had gross income in the basis period.
Don’t assume you’re exempt. New companies usually get the first PTR about 18 months after incorporation. If that window has passed and you’ve had chargeable profits, contact the IRD, request a return, and get the accounts ready. Waiting for a letter that may have gone to a stale address is how estimated assessments start.
No, they’re separate dates with separate penalties. BIR51 is due one month from the issue date, or your block-extension date. Payment comes later on the IRD assessment notice, which usually also charges provisional tax, an advance roughly equal to this year’s tax that’s credited against next year’s bill. Pay late and a 5% surcharge applies, rising a further 10% after six months.
Before your first BIR51 arrives, or as soon as April bulk issue hits an overloaded in-house calendar. We prepare the accounts, computation, and return, file through the right portal, and keep the year-end code and deadlines aligned so you’re not reconstructing the year in the last week.
