Domestic Priority for Patent and Trademark applications in Vietnam: from a statutory right to an incomplete legal mechanism

Abstract

Vietnamese IP law expressly permits priority based on a first application filed in Vietnam. Yet domestic priority appears to have seen little practical use and no stable, publicly documented examination practice has emerged. The framework provides relatively clear entry requirements but insufficient consequence rules concerning the fate of the first application, self-collision, partial priority, added subject matter, publication effects, multiple priorities and the same-subjectmatter test. 

1. The research problem

Article 91 of the IP Law states that the first application may have been filed in Vietnam. Article 12 of Decree 65/2023/ND-CP likewise recognizes a Vietnamese first filing, with twelve months for patents and six months for trademarks. The 2026 implementing rules also address priority based on first applications filed in Vietnam.

Domestic priority therefore exists as a statutory proposition. The principal gap concerns the legal consequences after such priority is claimed and accepted. 

2. An unclear conceptual foundation

Article 91 creates a national basis for priority from a Vietnamese filing, while Article 12 implements it in a Paris Convention-oriented structure. Paris Convention Article 4 principally protects subsequent filings in other Union countries. Domestic priority should therefore be treated as a national statutory right informed by, but not equated with, Paris priority. 

3.  No clear rule on the fate of the first application

If VN1 is filed on 1 January and VN2 on 1 October claiming VN1, the law does not clearly say whether VN1 must be withdrawn, is deemed withdrawn, may continue, or may proceed to grant. Article 90(3) is not tailored to applications of the same applicant linked by domestic priority. 

4.  Self-collision remains unresolved

If VN1 remains pending and VN2 obtains VN1's date, both may share the earliest relevant date. The law lacks a tailored rule preventing the priority application from defeating the later application, or vice versa, within the valid priority scope. 

5.  No developed new-first-application rule

Paris Convention Article 4C(4) permits a later filing in the same country to become a new first application only if the earlier filing has been withdrawn, abandoned or refused, has not been made public, leaves no rights outstanding and has not served as a priority basis. This prevents serial extension while permitting a controlled reset. Vietnamese law does not clearly transpose this logic. 

6.  Same subject matter is insufficiently defined

For patents, priority should be tested at claim and feature-combination level: only subject matter directly and unambiguously supported by the priority application should receive the earlier date. For trademarks, the test should address both the sign and the goods/services. The law does not clearly resolve later figurative additions, changes to the sign, or expansion of the specification. 

7.  Partial priority lacks an operational framework

Article 91 allows multiple priorities, but no detailed method exists for partial priority. If P1 discloses A+B and P2 contains A+B and A+B+C, the law should state that A+B may receive P1's date while the C-containing matter receives P2's filing date or another valid priority date. 

8.  Added matter and publication effects

Where VN1 is published and VN2 contains new matter not entitled to VN1's priority, the law should state whether and to what extent VN1 may become prior art against that new matter. For patents this may determine novelty and inventive step. 

9.  Preventing serial priority extension

Without a precise first-application rule, VN1→VN2→VN3 chains may be attempted. The WIPO Paris Convention Guide emphasizes that only the first application for the subject concerned starts the priority period, subject to the narrow Article 4C(4) exception. 

10.  Insufficient administrative infrastructure

The electronic system should link VN1 and VN2, record priority on a subject-matter basis, flag prior use of VN1 as a priority basis, show VN1's status and preserve an auditable examination record. 

11.  Proposed legislative model

Article 91 should define domestic priority expressly; priority should operate subject-matter by subject-matter; the law should govern the fate of VN1 and prevent double grants for overlapping exclusive scope; the Article 4C(4) logic should be incorporated; and examination guidelines should cover same subject matter, partial/multiple priority, priority mapping, self-collision and publication effects. 

12. Suggested wording for Article 91

“An applicant for a patent, industrial design or trademark in Vietnam may claim priority from a first application filed in Vietnam or from an application filed in a country or territory satisfying applicable treaty requirements. For domestic priority, the priority right shall extend only to the subject matter, or portion thereof, disclosed in the first application. Added subject matter shall not enjoy the first application's priority date unless supported by another valid priority claim.”

“The first application and the later priority-claiming application may coexist during examination; however, two protection titles shall not be granted for the same subject matter with overlapping exclusive scope. The Government shall prescribe procedures for election, amendment, withdrawal and resolution of conflicts between such applications.” 

13.  Suggested amendment to Article 12 of Decree 65

Article 12 should be divided into international priority and domestic priority. The domesticpriority section should regulate entitlement, the first application, time limits, evidence, partial and multiple priority, consequences for VN1, the new-first-application exception, prevention of serial extension, and consequences of an invalid priority claim. 

14.  Proposed examination guidance

IP Viet Nam should publish worked examples. Patent examiners should prepare claim-to-priority mapping and apply a direct-and-unambiguous disclosure test. Trademark examiners should map the sign and each item of goods/services. Full, partial or rejected priority should be expressly recorded in the file. 

15.  Conclusion

The principal defect is not the absence of a statutory basis for domestic priority; that basis exists. The problem is that the law defines the entrance to the regime more clearly than its legal consequences. Vietnam should establish a distinct regime addressing the fate of the first application, self-collision, partial priority, added matter, publication effects and prevention of serial priority chains./.

Pham Vu Khanh Toan 
Attorney-at-law and Registered IP Attorney 
Managing Partner, PHAM & ASSOCIATES

Principal references:  
- Vietnam IP Law, Consolidated Text No. 67/VBHN-VPQH dated 23 March 2026, Articles 90–91; Decree No. 65/2023/ND-CP, Article 12; Circular No. 10/2026/TT-BKHCN and Circular No. 20/2026/TT-BKHCN;
- Paris Convention, Article 4;
- WIPO Guide to the Application of the Paris Convention;
- EPO Enlarged Board of Appeal, G 2/98. 
- Research note: the observation that domestic priority has rarely been used and that no stable public examination practice has emerged is a practice-based observation. No comprehensive public database presently permits the absolute conclusion that no such case has ever been processed.