Tax Identification Number: Your Complete Guide to Understanding the TIN
- Published: 24 June 2025
- 7 min read
- Tax, Bookkeeping
Rodney Wong
Author
Rodney helps customers in Hong Kong navigate the details and benefits of our products and services, showing how technology can be a game changer for their business. A strong advocate for the power of the written word, he makes tech topics accessible, relevant, and, above all, practical—empowering entrepreneurs to pursue their big ideas.
A Tax Identification Number (TIN) is a unique number used to identify individuals and entities for tax payments and compliance purposes, enabling authorities to track taxable activities, ensure compliance, and share information across jurisdictions. This guide will help you understand the different types, why you need one, and how to get one.
Key Takeaways
- Hong Kong Identity Card (HKID) number for individuals and Business Registration (BR) number for businesses as their Taxpayer Identification Numbers (TINs) are essential for tax reporting, payments, compliance, and meeting international standards, especially for tax treaty purposes and identifying account holders across borders.
- Having a valid TIN is essential for tax compliance with financial institutions and employment benefits, as these identifying numbers facilitate proper reporting and tracking of tax obligations.
- TINs are required not only for local tax compliance but also for fulfilling international obligations under frameworks like CRS and FATCA, ensuring transparency with global financial institutions.
What Is a Tax Identification Number?
A Tax Identification Number (TIN) is a unique identifier assigned to individuals and legal entities for the purpose of administering tax laws. It plays a central role in modern tax systems by allowing authorities to track taxable activities, verify compliance, and facilitate the exchange of information on investment income, withholding, and earnings.
Osome’s accounting services ensure your business stays compliant with local tax reporting requirements. We manage your filings, records, and cross-border obligations so you can operate confidently and avoid costly mistakes.
Whether applied to personal income tax returns or business-related reporting, including wages, dividends, and other forms of compensation, the number serves as a foundational element in maintaining transparency, combating tax evasion, and supporting efficient revenue collection.
How TINs Are Utilised by Government Agencies?
In Hong Kong, the concept of a Taxpayer Identification Number is implemented differently compared to many other jurisdictions. Rather than issuing a separate, unique tax number, Hong Kong uses existing identifiers for tax purposes. These identifiers are employed by entities such as the Inland Revenue Department (IRD) to manage income tax returns, correspondence, and compliance.
TINs in Hong Kong are primarily used for: filing tax returns and correspondence with the IRD, registering for online tax services (e.g., eTAX), cross-border tax reporting and information exchange, identifying taxpayers during audits and compliance checks.
TIN for Individuals in Hong Kong
In Hong Kong, individuals do not receive a separate individual Taxpayer Identification Number. Instead, their Hong Kong Identity Card (HKID) number is used by the Inland Revenue Department (IRD) as their official Tax Identification Number (TIN) for all tax-related matters, including requesting documentation and processing deductions.
Hong Kong Identity Card (HKID) Number as TIN
The HKID number is the TIN for all Hong Kong residents and serves as a substitute for a social security number when accessing benefits or public employers. The HKID number follows a standard format: a letter (or two letters) followed by six digits and a check digit in parentheses
Example
HKID number — A123456(7)
eTAX System and TIN
The eTAX system is Hong Kong’s online platform for managing personal tax matters. To use eTAX, individuals must apply for an online account using their HKID number and an activation code issued by the IRD when a business is registered, enabling accurate mail tracking and legal compensation documentation. Once registered, they can file tax returns and manage paid taxes and any outstanding withholding.
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TIN for Entities in Hong Kong
In Hong Kong, business entities use their Business Registration (BR) number as their Taxpayer Identification Number or employer identification number. This number is essential for filing returns, regulatory compliance, and international reporting obligations.
Business registration number as TIN
The Business Registration (BR) number is the official Taxpayer Identification Number for all entities in Hong Kong, including limited companies, partnerships, and sole proprietorships. This number is required in all dealings with the IRD, from submitting profits tax returns and claiming relevant credits through electronic tax services such as eTAX.
Entities use the BR number as their other TIN when opening bank accounts, applying for licenses, and fulfilling tax reporting obligations with financial institutions for account holders and individuals receiving employment or passive income.
Verification of a BR number can be done through the IRD’s online Business Registration Number Enquiry System, which confirms the validity of the registration and its associated details.
Application process for TIN
Although Hong Kong does not issue a standalone TIN for businesses, the process of getting a BR number is effectively the application process. For incorporated companies, this is often done simultaneously with company incorporation through the Companies Registry.
The process requires submission of the appropriate forms, business details, and supporting identification documents. Once the application is approved and the relevant registration fees are paid, the certificate acts as proof of residency status.
Importance of TIN in Hong Kong's Tax System
The Taxpayer Identification Number (TIN) plays a vital role in Hong Kong’s tax administration by serving as the key reference for identifying taxpayers —both individuals and entities — within the IRD's system, as well as verifying employment history and claiming tax credits and benefits.
For individuals, the HKID number functions as the TIN, while for companies, the Business Registration (BR) number serves this purpose. These identifiers are used not only for domestic tax matters but also in fulfilling obligations under international agreements such as the Common Reporting Standard (CRS).
Failure to have or correctly use a TIN can lead to delays in tax processing, rejected filings, or inability to reach services like eTAX. In more serious cases, misuse or misreporting may result in penalties, investigations, or non-compliance, especially if a social security number is misused or missing.
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Osome's Role in TIN Assistance
Osome handles the full registration process to obtain the Business Registration (BR) number, which serves as the entity’s TIN. This includes coordinating with the Inland Revenue Department and Companies Registry. For individuals, Osome guides accessing the eTAX system, where the Hong Kong Identity Card (HKID) number functions as the TIN.
By streamlining these processes, Osome ensures clients stay compliant with local tax rules and international reporting standards, efficiently and accurately. Contact us today!
Summary
A Tax Identification Number (TIN) is a unique global code to identify taxpayers and ensure tax compliance. In Hong Kong, there is no separate system—individuals use their HKID number like a social security number, and businesses use their Business Registration (BR) number for tax purposes. TINs are critical for accurate taxpayer identification, both locally and globally.
Rodney helps customers in Hong Kong navigate the details and benefits of our products and services, showing how technology can be a game changer for their business. A strong advocate for the power of the written word, he makes tech topics accessible, relevant, and, above all, practical—empowering entrepreneurs to pursue their big ideas.
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FAQ
What is a Tax Identification Number (TIN)?
A TIN is a unique identifier used for tax purposes, crucial for ensuring accurate reporting and compliance.
What is a TIN number example?
The TIN is the HKID number for individuals (e.g., A123456(7)) and the BR number for companies (e.g., 12345678). These are used for tax filings and compliance.
How can a business obtain a TIN in Hong Kong?
A business in Hong Kong obtains its TIN by registering with the Inland Revenue Department (IRD).
Does Hong Kong have a national identification number?
Yes, Hong Kong has a national identification number known as the HKID number. This number also serves as the TIN for individuals in Hong Kong.
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