How To Handle An Employee With Two Personal Tax Codes

Key takeaways

• Starting July 1, 2025, the Personal Identification Number (PIN) will officially replace the Tax Identification Number (TIN), completely ending the issue of individuals having multiple tax IDs.
• Tax authorities will automatically merge all duplicate TINs into a single, unique PIN without requiring separate cancellation procedures.
• Businesses must immediately review their HR data and update their software systems to comply with the new regulation.
• All records, vouchers, and invoices that used an old TIN remain legally valid and do not need to be updated.
• Adapting early to this new rule helps businesses avoid operational disruptions and demonstrates modern, effective governance.

Duplicate TINs have long been a common challenge for businesses, often occurring when employees were issued more than one tax number after switching from an old ID card (CMND) to a new Citizen ID Card (CCCD) or registering for a TIN in multiple locations. With the new policy taking effect on July 1, 2025, all existing TINs will be synced and merged into a single, unique PIN.

How duplicate tax IDs will be handled during the transition to PINs

Resolving duplicate TINs will be handled automatically through a modern technology system, completely removing the complex administrative procedures of the past.

Tax authorities require taxpayers to update their PIN for all TINs issued to them before July 1, 2025, including any duplicates. It is critical that taxpayers proactively review all tax numbers they have ever been issued and ensure their information is updated completely.

Once the update is complete, the system will automatically cross-reference the information with the National Population Database and proceed to merge all tax information, obligations, and transaction histories into the single, unique PIN. This process is fully automated and requires no manual intervention from the taxpayer.

Old, duplicate, or redundant TINs will be marked as “merged” in the system and will no longer be active. Notably, taxpayers do not need to file any separate cancellation procedures for these old tax numbers. All benefits, tax data, and obligation histories will be fully transferred to the new PIN.

In cases where identification information is not yet synced or has discrepancies with the population database, taxpayers must follow the procedure to update and supplement their personal records as outlined in Article 25 of Circular 86/2024/TT-BTC. Tax authorities will only merge the data and officially use the PIN as the new tax identifier after ensuring the information is a perfect match.

The legal status of old documents

One of the biggest concerns for businesses is the legal validity of past transactions that used an old TIN.

According to Clause 4, Article 39 of Circular 86/2024/TT-BTC, all records, vouchers, and invoices that were created or used an old TIN before July 1, 2025, will remain legally valid. Businesses are not required to adjust the information on these completed transactions to reflect the new PIN.

This means all employment contracts, payrolls, tax reports, and personal income tax deduction invoices that used an old TIN continue to be legally effective. Businesses can confidently use these documents for audits, cross-referencing, or resolving any future tax-related issues.

However, for all new transactions that occur on or after July 1, 2025, businesses must use the PIN as the tax identifier to ensure legality and avoid compliance risks.

Frequently asked questions (FAQ)

Businesses often have many questions when dealing with duplicate TINs and the transition to the PIN system.

What are the common causes of duplicate tax IDs?

The issue of duplicate tax IDs typically happens for the following main reasons:

• Duplicate ID Card Numbers: Two different individuals share the same ID card number (CMND/CCCD) due to an administrative error or overlapping numbers from different provinces, causing the tax authority to issue them the same TIN.
• Changes in Personal Documents: An individual is issued multiple TINs after switching from an old CMND to a new CCCD or registering with different employers without declaring their existing TIN.
• Unauthorized Use: An individual’s or organization’s ID card number is used by someone else to register for a TIN without the owner’s consent.

How can I check for my personal tax ID online?

Use your ID card number (CMND/CCCD) to search on the General Department of Taxation’s e-portal (gdt.gov.vn), the e-Tax Portal (thuedientu.gdt.gov.vn), or mobile apps like iCanhan and eTaxMobile. If the search results show more than one TIN, you need to update your information to have them merged into your single PIN.

Can I choose which tax ID to keep?

No, you cannot choose which TIN to keep. Under the new regulations effective July 1, 2025, all old TINs will be merged into a single, unique identifier: the 12-digit PIN on your Citizen Identity Card. This rule ensures consistency across the entire national tax management system.

What if the information on my old tax ID doesn’t match my citizen ID card?

You need to complete the procedure to change your tax registration information through the e-Tax Portal, the iCanhan or eTaxMobile app, or directly at a tax office to update it with the correct information from your Citizen ID Card. Once the updated information matches the National Population Database, your TIN will be synced with your PIN. This is also a key factor in effective HR systems integration.

The transition to a PIN-based tax ID is a mandatory step in the government’s digitalization process. This is no longer just an administrative task to be handled—it is a systemic compliance requirement. Leaders should immediately direct their HR and accounting departments to conduct a comprehensive review and ensure their systems are compatible with the new regulation. Adapting early not only helps avoid the consequences of having two tax IDs but also affirms your company’s capacity for modern governance and legal compliance. To ensure this transition goes smoothly, businesses can consider a professional payroll service that is fully equipped to handle the latest legal requirements.