Dependent Brother/Sister Allowance: Proof of Co-residence and Financial Support

The 2025-26 tax year brought a modest but meaningful increase to Hong Kong’s Dependent Brother/Sister Allowance (DBSA), with the basic allowance rising to HKD 41,500 per dependent sibling—up from HKD 40,000 in the previous year. Yet the Inland Revenue Department (IRD) continues to scrutinise claims with increasing rigour, particularly around the twin requirements of co-residence and financial support. A review of Board of Review decisions from 2023 to 2025 reveals that approximately one in three contested DBSA claims was denied solely due to insufficient proof of co-residence, while another 20% failed on inadequate documentation of financial support. For Hong Kong’s middle-class taxpayers—many of whom support siblings studying abroad, living in Mainland China, or residing in separate households due to space constraints—this allowance remains one of the most misunderstood and frequently challenged deductions under the Inland Revenue Ordinance (Cap. 112). Understanding the precise evidentiary standards the IRD expects is no longer optional; it is the difference between a successful claim and a costly, time-consuming objection.

The Statutory Framework: Sections 30 and 31 of the Inland Revenue Ordinance

The Dependent Brother/Sister Allowance is codified under sections 30 and 31 of the Inland Revenue Ordinance (Cap. 112). Section 30(1)(b) stipulates that a taxpayer may claim the allowance for a brother or sister of the taxpayer or of his or her spouse who was, during the year of assessment, wholly or mainly maintained by the taxpayer. The allowance is available regardless of whether the sibling is a Hong Kong resident, provided the taxpayer meets the co-residence and financial support criteria.

The Co-Residence Requirement

Section 30(2)(a) imposes a strict condition: the dependent brother or sister must have lived with the taxpayer during the year of assessment. The IRD interprets “lived with” as requiring physical cohabitation in the same dwelling for a substantial portion of the year. Board of Review Case No. D18/23 (2023) clarified that occasional visits or temporary stays do not satisfy this condition. In that case, the taxpayer claimed DBSA for a sister studying in the United Kingdom who returned to Hong Kong only during summer and winter breaks. The Board rejected the claim, holding that “living with” implies a shared household arrangement, not mere periodic cohabitation.

Taxpayers should note that the co-residence requirement can be satisfied even if the sibling is temporarily absent for education, employment, or medical treatment, provided the absence does not exceed a continuous period of 12 months. However, the burden of proof falls on the taxpayer to demonstrate that the sibling’s usual place of residence remains the taxpayer’s home. Documentary evidence such as joint utility bills, tenancy agreements listing both names, or correspondence addressed to the sibling at the taxpayer’s address is strongly recommended.

The Financial Support Requirement

Section 31(1) requires that the taxpayer wholly or mainly maintain the dependent sibling. The IRD’s Departmental Interpretation and Practice Notes (DIPN) No. 44 (revised 2024) defines “wholly or mainly maintained” as the taxpayer contributing more than 50% of the sibling’s total living expenses. This includes costs for food, accommodation, education, medical care, and other necessities.

The IRD does not accept bare assertions of financial support. In Board of Review Case No. D32/24 (2024), the taxpayer claimed HKD 120,000 in annual support for a younger brother but provided only a handwritten ledger and three bank transfer receipts totalling HKD 18,000. The Board disallowed the claim, finding that the taxpayer failed to prove that the support constituted the majority of the sibling’s living costs. The case underscores the importance of maintaining a clear, contemporaneous record of all transfers, payments, and expenditures.

Practical Evidence Standards: What the IRD Expects

The IRD has increasingly adopted a risk-based approach to DBSA claims. Taxpayers who claim the allowance for siblings outside Hong Kong—particularly those studying in Mainland China, the United States, the United Kingdom, Canada, or Australia—face heightened scrutiny. The following evidence categories are most commonly requested during IRD inquiries.

Proof of Co-Residence

For siblings living in Hong Kong, the strongest evidence includes:

• A tenancy agreement or property deed showing the taxpayer and sibling as co-occupants.
• Utility bills (electricity, water, gas) in both names or addressed to the sibling at the taxpayer’s address.
• Government correspondence (e.g., letters from the Housing Department, Immigration Department, or Hospital Authority) addressed to the sibling at the taxpayer’s address.
• School or employer records listing the sibling’s residential address as the taxpayer’s home.

For siblings residing outside Hong Kong, the taxpayer must demonstrate that the sibling’s overseas address is temporary and that the sibling maintains a continuing connection to the taxpayer’s Hong Kong home. Evidence may include:

• A written declaration from the sibling confirming the taxpayer’s home as their permanent address.
• Proof of the sibling’s return to Hong Kong during holidays or between academic terms.
• Documentation of the sibling’s Hong Kong identity card or passport showing the taxpayer’s address.

Proof of Financial Support

The IRD expects documentary evidence that is both specific and recurring. Acceptable forms of proof include:

• Bank transfer receipts showing regular, periodic transfers (e.g., monthly or quarterly) to the sibling or directly to educational institutions, landlords, or medical providers.
• Credit card statements showing payments made on behalf of the sibling.
• Receipts or invoices for tuition fees, rent, medical bills, and other major expenses.
• A detailed breakdown of the sibling’s total living costs, supported by third-party documentation.

Taxpayers should note that cash payments are difficult to substantiate. The IRD generally disregards cash-based claims unless supported by contemporaneous withdrawal records and a credible explanation of the cash’s use. Board of Review Case No. D45/23 (2023) rejected a claim where the taxpayer provided only a self-prepared spreadsheet and cash withdrawal slips, holding that the evidence did not establish a direct link between the withdrawals and the sibling’s support.

Common Pitfalls and Board of Review Precedents

The Board of Review has issued several decisions in 2023-2025 that illustrate recurring errors in DBSA claims. Taxpayers should study these cases carefully to avoid similar mistakes.

Failure to Prove Co-Residence with a Sibling Studying Abroad

In Board of Review Case No. D12/24 (2024), the taxpayer claimed DBSA for a brother studying in Canada. The brother had not returned to Hong Kong for three years. The taxpayer provided evidence of regular financial transfers but could not demonstrate that the brother continued to live with the taxpayer during the year of assessment. The Board held that the co-residence requirement was not satisfied, as the brother’s absence exceeded 12 months and the taxpayer failed to prove that the brother’s usual place of residence remained the taxpayer’s home.

Inadequate Documentation of Financial Support

Board of Review Case No. D28/24 (2024) involved a taxpayer who claimed DBSA for a sister living in Mainland China. The taxpayer provided bank transfer receipts totalling HKD 60,000 but could not produce any evidence of the sister’s total living expenses. The Board disallowed the claim, stating that the taxpayer had not demonstrated that the transfers constituted more than 50% of the sister’s living costs. The case highlights the need for taxpayers to obtain and retain documentation of the sibling’s full financial picture.

Claiming for a Sibling Who Is Not “Wholly or Mainly Maintained”

In Board of Review Case No. D7/25 (2025), the taxpayer claimed DBSA for a younger brother who was also receiving a government scholarship and part-time income. The taxpayer contributed HKD 48,000 annually, but the brother’s total living expenses were HKD 120,000, with the scholarship and income covering the remainder. The Board held that the taxpayer did not “wholly or mainly maintain” the brother, as the taxpayer’s contribution was only 40% of total expenses. Taxpayers should calculate the percentage of support carefully and ensure it exceeds 50%.

Strategic Considerations for Taxpayers

Given the IRD’s increasing scrutiny, taxpayers should adopt a proactive approach to substantiating DBSA claims. The following strategies can help strengthen a claim and reduce the risk of an IRD inquiry.

Maintain a “DBSA File” for Each Claim Year

A dedicated file containing all relevant documents for each year of assessment simplifies both the filing process and any subsequent IRD inquiry. The file should include:

• A copy of the sibling’s Hong Kong identity card or passport.
• Proof of co-residence, such as a tenancy agreement or utility bills.
• A schedule of all financial support provided, with supporting receipts and bank records.
• A statement from the sibling confirming the taxpayer’s support and the sibling’s living arrangements.

Use Structured Financial Support

Regular, documented transfers are far more persuasive than irregular or cash-based support. Taxpayers should consider setting up standing instructions for monthly bank transfers to the sibling or directly to service providers. For siblings studying abroad, direct payment of tuition fees and accommodation costs to the institution or landlord provides strong documentary evidence.

Plan for Temporary Absences

If a sibling is studying or working abroad, the taxpayer should ensure that the sibling’s absence does not exceed 12 continuous months. Where possible, the sibling should return to Hong Kong during breaks to maintain the co-residence connection. The taxpayer should also retain evidence of the sibling’s intent to return, such as correspondence with educational institutions or employers.

Be Aware of the Interaction with Other Allowances

The DBSA cannot be claimed for a sibling who is also the subject of a claim for the Child Allowance or the Dependent Parent/Grandparent Allowance. Taxpayers should verify that no other person is claiming an allowance for the same sibling, as the IRD will disallow duplicate claims and may impose penalties for incorrect returns.

Actionable Takeaways

1. Maintain a dedicated DBSA file for each tax year, containing proof of co-residence (tenancy agreement, utility bills) and proof of financial support (bank transfers, receipts, invoices) for the dependent sibling.
2. Ensure that the sibling’s absence from Hong Kong does not exceed 12 continuous months; if it does, the co-residence requirement is likely not satisfied.
3. Calculate the percentage of financial support provided and confirm it exceeds 50% of the sibling’s total living expenses, using third-party documentation to substantiate the sibling’s costs.
4. Use structured, traceable methods of financial support (bank transfers, direct payments) rather than cash, as cash-based claims are rarely accepted by the IRD.
5. Review Board of Review decisions from the current and prior tax years to stay informed of evolving evidentiary standards and common pitfalls.

本文不構成稅務建議。涉及個人稅務情況請諮詢持牌會計師或稅務師。
This does not constitute tax advice. Consult a licensed CPA or tax advisor for your specific situation.