Hong Kong Profits Tax · BIR51 · e-Filing
From your client's books to a reviewed tax computation.
A3T reads the files you already have — trial balances, ledgers, audited financial statements and last year's computation — and prepares the working trial balance, tax computation, covering letter, BIR51 and e-filing package for your review.
Built for Hong Kong accounting and tax practices.
Year of assessment 2025/26
Schedule Profits Tax Computation
- 1,250,000
Profit before taxation
Audited FS · Income statement
- 86,400
Add: Depreciation
Audited FS · Note 9
- 12,000
Add: Fines and penalties
General ledger · 3 postings
- (94,300)
Less: Depreciation allowances
Schedule Depreciation Allowances
- 1,254,100
Assessable profits
Computed
- 103,463
Tax at 8.25% (first tier)
Two-tiered rates
See it in action
A profits tax computation, prepared end to end
Watch A3T take a year's files from upload to a finished computation and BIR51 — and see how each figure can be traced back to where it came from.
How it works
What goes in, what comes out
No re-keying and no new templates. Upload the documents a profits tax engagement already produces, and A3T does the preparation.
You upload
- Prior-year working trial balance
- Prior-year tax computation
- Prior-year BIR51 and IRD assessment notice
- Management accounts and general ledger
- Audited financial statements and audit working papers
Audited statements, working papers and the assessment notice are optional — each one that is provided is used to check the others.
You review
Working trial balance
Mapped to standard accounts, tied to the ledger
Tax computation
Every supporting schedule, downloadable to Excel
Covering letter
Drafted from your answers, in Word
BIR51 profits tax return
Drawn on the IRD's official form
e-Filing package
iXBRL statements and computation, plus S-forms in XML
- Step 1
Upload
Last year's and this year's files, as you already have them — Excel, PDF or Word, including scanned statements.
- Step 2
Answer
A short questionnaire, pre-filled. Each suggested answer shows the evidence and prior-year treatment behind it.
- Step 3
Review
Check the computation schedule by schedule. Adjust, add a note, or re-run with post-audit figures as a new version.
- Step 4
File
Download the computation, covering letter and BIR51, or the validated e-filing package for the IRD.
Profits Tax e-filing
Ready for e-filing, checked before you upload
When the computation is signed off, A3T prepares the electronic filing: the financial statements and the tax computation in iXBRL, and any supplementary forms in the IRD's XML format — validated, and packaged in one download.
iXBRL, tagged to the IRD taxonomy
Every figure in the financial statements and the tax computation is tagged against the IRD's taxonomy for the year, and each tag can be reviewed on screen.
Validated before download
Each file is checked against business rules and an XBRL validator, and profit before tax is compared across the two documents. The package is produced only once everything passes.
Supplementary forms S1, S2 and S19
Completed on screen, pre-filled from last year's forms, checked with the IRD's own completeness rules and exported to the XML the e-filing service expects.
One package, two audiences
The files to upload to the IRD in one folder; a client copy showing the tag on every figure in another.
01_For_IRD/
- Tax computationiXBRL
- Financial statementsiXBRL
- Supplementary form S1XML
02_For_client/
- Tagging reportsHTML
Why A3T
Automation you can put your name to
A tax computation is only as good as the reviewer's ability to check it. A3T is built so that every number can be checked.
AI reads. Rules compute.
AI is used only to read, classify and map your documents. Every tax figure is calculated by a deterministic engine — the same answers always give the same computation.
Every figure has a source
Each number traces to a cell in an uploaded file, a questionnaire answer, a prior-year carry-forward or a tax rule. Nothing is an unexplained guess.
Ties to the audited accounts
The profit and loss account follows the audited income statement section by section — not just the bottom line — so a misclassification can't hide behind a matching profit.
Questions only where judgement is needed
New accounts, stamp duty, fixed-asset additions and other items that change the tax are raised as risk items with their evidence. The rest carries forward.
Last year, carried forward properly
Prior-year treatments, losses brought forward and provisional tax are read from last year's computation and, where you upload it, checked against the IRD's assessment notice.
Built for review
Maker–checker approval, comments and versioned computations, so a partner signs off on exactly the version being filed.
Contact us
See A3T on your own practice's work
Tell us a little about your firm and we'll arrange a walkthrough and answer any questions about getting started.
- A live demo of a full computation, start to finish
- How A3T fits your existing review and sign-off process
- Access for your team
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