Hong Kong-Taiwan Double Taxation Relief: Tax Compliance for Cross-Strait Professionals

For the Hong Kong-based professional earning income from Taiwan, the distinction between tax avoidance and tax compliance has narrowed considerably since 2023. The Taiwan Ministry of Finance’s decision to extend the automatic exchange of financial account information (AEOI) to include Hong Kong, effective from tax year 2024, means that income previously unreported to Taiwan’s tax authorities is now visible through data matching with the Hong Kong Inland Revenue Department (IRD). Simultaneously, Hong Kong’s Inland Revenue Ordinance (Cap. 112) continues to enforce its territorial source principle, creating a compliance trap: income sourced in Taiwan but earned by a Hong Kong resident may be taxable in both jurisdictions unless specific relief is claimed. For the cross-strait professional—whether a Hong Kong tax resident with a Taiwan work permit, a Taiwanese national holding a Hong Kong permanent identity card, or a dual resident under the Taiwan-Hong Kong Economic and Cultural Co-operation Council agreements—the 2025 filing season is the first where failure to disclose Taiwan-source income to the IRD, or Hong Kong-source income to the Taiwan tax authorities, carries a materially higher risk of audit and penalty. This article sets out the operative tax positions, treaty relief mechanisms, and filing obligations for the cross-strait professional.

The Territorial Source Principle and Taiwan’s Worldwide Taxation Regime

Hong Kong’s Position: Source-Based Taxation Only

Hong Kong’s Inland Revenue Ordinance (Cap. 112) imposes salaries tax under Section 8(1) on income “arising in or derived from Hong Kong.” For the Hong Kong tax resident who performs services in Taiwan, the critical question is whether the employment income is sourced in Hong Kong or Taiwan. The IRD’s Departmental Interpretation and Practice Notes (DIPN) No. 10 (Revised 2020) clarifies that employment income is sourced where the services are physically performed. If a Hong Kong resident spends 60 days or more in a tax year working in Taiwan, the income attributable to those Taiwan workdays is considered Taiwan-source income and is not subject to Hong Kong salaries tax. Conversely, income for services performed in Hong Kong remains taxable in Hong Kong, regardless of the employer’s location.

The operative position for the professional working across the strait is that Hong Kong will only tax the portion of employment income attributable to services performed in Hong Kong. The IRD does not tax worldwide income; it taxes only Hong Kong-source income. This is a fundamental difference from the US or Mainland China systems. For a Hong Kong tax resident with a Taiwan employer, the IRD will require a breakdown of workdays between Hong Kong and Taiwan, supported by travel records, employment contracts, and payslips. The IRD’s Field Audit and Investigation Division has, since 2022, increased scrutiny of professionals claiming full Hong Kong-source treatment while maintaining a Taiwan residence permit.

Taiwan’s Position: Worldwide Taxation with a Foreign Tax Credit

Taiwan’s Income Tax Act (Article 2) imposes individual income tax on the worldwide income of Taiwan tax residents. A Taiwan tax resident is defined as an individual who has a domicile in Taiwan and habitually resides there, or who resides in Taiwan for 183 days or more in a tax year. For the Taiwanese national living in Hong Kong but retaining a Taiwan household registration, the Taiwan tax authorities will presume tax residency unless the individual can demonstrate that their “centre of vital interests” has moved permanently to Hong Kong. The Taiwan Ministry of Finance’s Tax Ruling No. 09804523290 (2009) confirms that a Taiwan national who works abroad but maintains a Taiwan domicile remains a Taiwan tax resident.

The Taiwan tax resident must report worldwide income, including Hong Kong employment income, on their annual Taiwan individual income tax return (Form 75). Taiwan operates a foreign tax credit (FTC) system under Article 3 of the Income Tax Act, allowing a credit for foreign income taxes paid on the same income, capped at the Taiwan tax attributable to that foreign-source income. For the 2024 tax year, Taiwan’s individual income tax rates range from 5% to 40%, with a standard deduction of NTD 124,000 for a single filer. The FTC is claimed on Schedule C of the return, supported by a certificate of tax paid from the Hong Kong IRD.

The Double Taxation Relief Mechanism: The Taiwan-Hong Kong Arrangement

Since 2019, the Taiwan-Hong Kong Double Taxation Arrangement (DTA) has been in effect, providing a framework for eliminating double taxation on income earned by residents of one jurisdiction from sources in the other. The DTA is not a formal treaty but a bilateral administrative arrangement between the Taipei Economic and Cultural Office (TECO) in Hong Kong and the Hong Kong Economic, Trade and Cultural Office (HKETCO) in Taiwan. Despite its non-treaty status, the IRD and Taiwan’s Ministry of Finance have confirmed that the DTA’s provisions are binding on both tax administrations.

Under the DTA, employment income is taxable only in the resident state (the state where the employee is a tax resident) unless the employment is exercised in the other state. If the employment is exercised in the other state, income derived from that employment may be taxed in that other state. However, Article 14(2) of the DTA provides an exemption: income derived by a resident of one jurisdiction from employment exercised in the other jurisdiction is taxable only in the resident jurisdiction if:

• The employee is present in the other jurisdiction for 183 days or less in any 12-month period commencing or ending in the tax year concerned; and
• The employer is not a resident of the other jurisdiction; and
• The remuneration is not borne by a permanent establishment (PE) of the employer in the other jurisdiction.

For the Hong Kong resident working in Taiwan, if the Hong Kong employer has no PE in Taiwan and the professional spends 183 days or less in Taiwan, the income remains taxable only in Hong Kong. Conversely, if the Taiwan employer has a PE in Hong Kong—such as a branch office or a fixed place of business—the income may become taxable in Hong Kong under the PE attribution rules.

Filing Obligations for the Cross-Strait Professional

Hong Kong: Salaries Tax Return and the Foreign Income Disclosure

The Hong Kong tax resident earning income from Taiwan must file a salaries tax return (Form BIR60) annually. The return requires the taxpayer to declare all employment income, but the IRD will only assess tax on the Hong Kong-source portion. The professional must provide a breakdown of workdays between Hong Kong and Taiwan, supported by a tax computation schedule. The IRD’s Practice Note on Foreign Income (2022) advises that where the taxpayer claims a portion of income is not subject to Hong Kong tax due to the territorial source principle, the onus is on the taxpayer to prove the source. The IRD will accept a log of travel dates, employer letters confirming work locations, and payslips showing separate Hong Kong and Taiwan components.

For the 2024-25 tax year (assessment year ending 31 March 2025), the Hong Kong salaries tax rates are 2% on the first HKD 50,000 of net chargeable income, 6% on the next HKD 50,000, 10% on the next HKD 50,000, 14% on the next HKD 50,000, and 17% on the remainder, capped at 15% of total assessable income (standard rate). The IRD will not allow a deduction for Taiwan tax paid on the same income, as Hong Kong does not provide a foreign tax credit. The relief comes from the source rule: the Taiwan-source portion is simply not taxable in Hong Kong.

Taiwan: Annual Individual Income Tax Return and the Foreign Tax Credit

The Taiwan tax resident must file Form 75 by 31 May of the following year. For the 2024 tax year (filed in 2025), the Taiwan tax authorities will require disclosure of all Hong Kong employment income, converted to NTD at the central bank’s annual average exchange rate (for 2024, approximately NTD 3.95 to HKD 1). The taxpayer claims the foreign tax credit on Schedule C, attaching a certified copy of the Hong Kong tax assessment or a letter from the IRD confirming the Hong Kong tax paid. The credit is limited to the Taiwan tax attributable to the Hong Kong income, calculated as (Hong Kong income / total worldwide income) × Taiwan tax before credit.

The Taiwan tax authorities have, since the 2023 tax year, increased audit activity on Hong Kong-source income, particularly for professionals who hold Hong Kong permanent identity cards but maintain Taiwan household registration. The Taiwan Ministry of Finance’s 2023 Annual Report on International Tax Compliance noted that 127 cases of unreported Hong Kong income were identified through AEOI data matching, resulting in NTD 84 million in back taxes and penalties.

The AEOI Impact: What the Taiwan Tax Authorities Now See

The automatic exchange of financial account information between Hong Kong and Taiwan, effective from 1 January 2024, means that Taiwan tax authorities receive annual data on Taiwan tax residents holding financial accounts in Hong Kong. The data includes account balances, interest, dividends, and gross proceeds from asset sales. For the cross-strait professional, this means that Hong Kong bank accounts, investment portfolios, and insurance policies are now visible to the Taiwan tax authorities. The IRD’s Common Reporting Standard (CRS) Portal confirms that Hong Kong financial institutions must report accounts held by Taiwan tax residents to the IRD, which then transmits the data to Taiwan’s Ministry of Finance.

The operative position is that any Hong Kong-sourced investment income—such as dividends from Hong Kong stocks, interest on Hong Kong bank deposits, or rental income from Hong Kong property—must be declared on the Taiwan tax return. Failure to do so carries a penalty of up to three times the underpaid tax under Article 110 of the Taiwan Income Tax Act.

Practical Compliance Strategies for the Cross-Strait Professional

Structuring Employment to Minimise Double Taxation

The most effective strategy for the Hong Kong-based professional earning income from Taiwan is to structure the employment arrangement to fall within the 183-day exemption under Article 14(2) of the DTA. This requires:

• The employer to be a Hong Kong resident (i.e., incorporated and managed in Hong Kong) with no PE in Taiwan.
• The professional to spend no more than 183 days in Taiwan in any 12-month period.
• The remuneration to be paid by the Hong Kong employer and not charged to a Taiwan PE.

For the professional who must spend more than 183 days in Taiwan, the income becomes taxable in Taiwan. In that case, the professional should ensure that the Hong Kong employer does not have a Taiwan PE, so that the income is not also taxable in Hong Kong under the PE attribution rules. The professional should also claim the foreign tax credit in Taiwan for any Hong Kong tax paid on the same income.

Managing Tax Residency to Avoid Dual Residency

A dual residency situation—where the professional is considered a tax resident of both Hong Kong and Taiwan—creates a compliance nightmare. The DTA’s tie-breaker rule (Article 4) provides that an individual who is a resident of both jurisdictions shall be deemed a resident only of the jurisdiction where the individual has a permanent home available. If the individual has a permanent home in both jurisdictions, the individual is deemed a resident of the jurisdiction where the individual’s personal and economic relations are closer (centre of vital interests). If that cannot be determined, the individual is deemed a resident of the jurisdiction where the individual has a habitual abode. If the individual has a habitual abode in both, the individual is deemed a resident of the jurisdiction of which the individual is a national.

For the Taiwanese national living in Hong Kong, the tie-breaker analysis often favours Taiwan if the individual maintains a Taiwan household registration, owns property in Taiwan, and has family there. The professional should consider relinquishing Taiwan household registration if the centre of vital interests has genuinely moved to Hong Kong. This is a non-reversible step and should only be taken after consultation with a Taiwan tax advisor.

Record-Keeping and Documentation

The IRD and Taiwan’s Ministry of Finance both require contemporaneous documentation to support tax positions. The cross-strait professional should maintain:

• A daily travel log showing dates of presence in Hong Kong and Taiwan.
• Employment contracts specifying the place of work and the employer’s tax residence.
• Payslips showing the allocation of income between Hong Kong and Taiwan workdays.
• Copies of tax returns filed in both jurisdictions.
• Certificates of tax paid from the IRD and Taiwan’s tax authorities.

The IRD’s Field Audit Manual (2023) states that where a taxpayer fails to maintain adequate records, the IRD may estimate the Hong Kong-source income based on a 50:50 split of workdays, which may be unfavourable to the taxpayer.

Actionable Takeaways

1. File a Hong Kong salaries tax return (BIR60) for the 2024-25 tax year by 2 June 2025, disclosing all employment income but excluding the Taiwan-source portion supported by a workday breakdown.
2. File a Taiwan individual income tax return (Form 75) by 31 May 2025, disclosing all Hong Kong employment income and claiming the foreign tax credit with a certified Hong Kong tax assessment attached.
3. Restructure employment to ensure the Hong Kong employer has no permanent establishment in Taiwan and that the professional spends no more than 183 days in Taiwan to qualify for the DTA exemption under Article 14(2).
4. Review Taiwan household registration status and consider relinquishing it if the centre of vital interests has permanently moved to Hong Kong, to avoid dual residency and double taxation.
5. Maintain a daily travel log and contemporaneous employment records for at least seven years, the statute of limitations for both the IRD and Taiwan’s Ministry of Finance.

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.