The 7-Year Business-Records Rule: What to Keep and in What Form

Hong Kong profits tax is administered under the Inland Revenue Ordinance (IRO). Section 51C of the IRO requires a person carrying on a trade, profession, or business in Hong Kong to keep sufficient records of their business transactions and underlying activities so that the assessable profits of the business can be readily ascertained. The retention period runs for at least 7 years after the completion of the transaction, act, or operation to which the records relate. In practice, that means records for a year of assessment should be retained for at least 7 years from the end of that year of assessment.

This guide sets out what needs to be kept, in what form, and what the IRD typically asks for first when a review opens. It complements — rather than replaces — a companion field-audit response playbook.

The Duty Under Section 51C

The statutory obligation is not simply to keep paperwork. It is to keep records of every transaction and underlying act sufficient to enable assessable profits to be readily ascertained. The practical implications:

• Sufficient, not exhaustive. Records must be enough to work out the profit position. They do not need to capture every internal email, but they do need to capture the documents that drive revenue, expense, asset, and liability figures.
• Readily ascertainable. An IRD officer should be able to follow the trail from the filed return back to source documents without reconstructing the picture from fragments.
• 7 years minimum. Retention is at least 7 years after the completion of the transaction or act the records relate to. Earlier destruction can give rise to serious consequences if a review or dispute later opens.
• Translation and access. Records may be required to be produced within a reasonable time. Where records are in a language other than Chinese or English, translation obligations can be triggered. Records must be kept in Hong Kong or be accessible from Hong Kong.

Electronic vs Paper Records

The IRO does not prescribe a medium. Both paper and electronic records are acceptable provided they satisfy the s.51C standard. In practice, electronic records dominate modern operations, and the IRD's own guidance accepts digital formats where integrity and retrievability are demonstrable.

Key points when records are held electronically:

• Audit trail. Changes to underlying data should be traceable. Systems that allow silent overwriting of original entries weaken the position.
• Source documents. Scanned images of paper source documents (invoices, receipts, contracts) are generally accepted, provided the scans are legible and the originals are retained or destroyed only on a documented basis.
• Backup and format stability. Records should be stored on media that remains readable. Formats that depend on obsolete or proprietary software should be migrated before support lapses.
• Access during review. When IRD requests records, electronic records are typically requested in a usable form (CSV, XLSX, PDF, or native accounting-file exports) along with a mapping of how the data ties to the filed return.

Paper records are acceptable but bring their own practical issues: storage costs, retrieval time, and the risk of loss or damage. The medium matters less than the integrity, completeness, and retrievability of what is kept.

What the IRD Asks for First in a Review

Reviews and field visits tend to follow a familiar opening pattern. The first requests usually focus on:

1. The accounting system itself. The general ledger, chart of accounts, trial balance, and a reconciliation from the filed profits tax computation back to the financial statements and back to source.
2. Bank records. Business bank statements for the periods under review, plus bank reconciliation files and any inter-account transfer listings.
3. Sales and revenue records. Invoices issued, sales day-book or equivalent, credit notes, and the supporting documents that reconcile revenue per the ledger to bankings.
4. Purchases and expense records. Supplier invoices, expense claims, payroll records, MPF contributions, and rental or lease agreements for the business premises.
5. Fixed-asset register and depreciation schedules. Additions, disposals, depreciation methodology, and the supporting invoices.
6. Stock records (where applicable). Stock counts, perpetual records, and the basis on which closing stock is valued.

Requests usually widen from this base. Where the opening set of records reconciles cleanly, the scope of the review tends to stay narrow. Where reconciliations break down at the front end, the breadth of subsequent requests typically expands.

Retention Checklist by Record Type

A workable default checklist for a Hong Kong business carrying on a trade:

• Sales and revenue. Invoices issued, credit notes, sales contracts, point-of-sale records, and bankings reconciliations. Retain 7 years from the end of the year of assessment in which the transaction occurs.
• Purchases and expenses. Supplier invoices, receipts, petty cash records, expense claims with supporting documents, and corporate credit-card statements. Retain 7 years.
• Payroll. Employment contracts, payslips, MPF contribution records, IR56 forms issued to employees, and payment records to staff. Retain 7 years after the end of the employment or the year of assessment, whichever is later.
• Bank records. Business bank statements, bank reconciliation working papers, and loan or facility agreements. Retain 7 years.
• Fixed assets. Asset register, purchase invoices, disposal documents, and depreciation workings. Retain 7 years after the asset is disposed of.
• Stock. Stock counts, perpetual inventory records, and stock valuation workings. Retain 7 years.
• Corporate and statutory. Annual returns, board minutes, shareholders' resolutions, and any documents supporting inter-company or related-party transactions. Retain 7 years.
• Tax filings. Profits tax returns and computations, tax assessments, and any correspondence with the IRD. Retain 7 years from the date of the final determination of the year.

Records relating to long-lived matters — property titles, intellectual property assignments, and litigation files — should be kept on a longer horizon driven by the underlying transaction, not by the 7-year rule alone.

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