Vietnamese tax codes explained
1. What is an MST?
Every company and taxpayer in Vietnam has a mã số thuế (MST). Before signing a contract or paying a supplier, checking the MST confirms the company's legal name and registered address, which must match the details on its e-invoices.
- Company: 10 digits, identical to the enterprise registration number; it never changes.
- Branch or dependent unit: 13 digits in the form 0100112437-001.
2. Personal tax codes
Since 1 July 2025, Vietnamese citizens use their 12-digit personal identification number as their tax code; older 10-digit personal codes have been mapped to it by the tax authority.
3. Tax codes for foreigners
Foreign employees receive a 10-digit personal tax code. Employers normally register it within 10 working days of the tax obligation arising, so you can deduct dependents and complete your annual PIT finalisation.
Frequently asked questions
What is a Vietnamese tax code (MST)?
Mã số thuế (MST) is the tax identification number issued by the Vietnamese tax authority. For companies it has 10 digits and is the same as the enterprise registration number; branches have 13 digits (10 digits, a dash and 3 more).
How do I check that a tax code is valid?
The 10th digit of a Vietnamese tax code is a check digit calculated from the first nine digits. This tool rejects codes with a wrong check digit before searching, which catches most typos.
What is the personal tax code for Vietnamese citizens now?
Since 1 July 2025, Vietnamese citizens use their 12-digit personal identification number (on the CCCD citizen ID card) as their tax code. Foreigners still receive a 10-digit personal tax code, usually registered by their employer.
Where does the company data come from?
Company names and addresses come from a public business lookup API provided by VietQR, which mirrors data from the national business registry. For legal purposes, confirm on the tax authority portal tracuunnt.gdt.gov.vn.