Who is Eligible to File a Patent in Bulgaria
Any applicant who designated Bulgaria in a PCT application is eligible to enter the national phase. Qualified applicants include:
- Individual inventors
- Bulgarian and foreign corporations
- Universities and research institutions
- Startups and SMEs
- Joint applicants and co-owners
- Legal successors and assignees
Representation Requirement: Foreign applicants must appoint a Bulgarian patent attorney authorized to represent them before the Bulgarian Patent Office. Only registered representatives can prosecute a patent application and communicate with the BPO.
Entitlement Requirements: Applicants must ensure that some of these factors
- Inventors are correctly identified.
- If the applicant is not the inventor, an assignment or entitlement declaration is required.
- Assignment documents do not require notarization or legalization unless specifically requested.
Accurate entitlement documentation is essential for grant and later enforcement.
Strict Deadline for Bulgaria Patent Filing– 30 / 31-Month Rule
Bulgaria follows the standard PCT deadline:
31 months from the earliest priority date to enter the national phase.
Applicants must file the national application, submit required translations, and pay the national fees within this timeframe.
Extensions After the 30 / 31-Month Deadline
Bulgaria does not provide a routine extension for national phase entry.
If the 31-month deadline is missed:
- The application is considered withdrawn for Bulgaria.
- Restoration is generally not available except in rare cases where reinstatement may be justified as unintentional.
Applicants should treat the 31-month deadline as strict and final.
Filing Language for Bulgaria Patent Application
The official language of the Bulgarian Patent Office is Bulgarian.
To enter the national phase:
- The entire PCT application (specification, claims, abstract, Patent drawings) must be translated into Bulgarian.
- Translation quality is critical, as the Bulgarian text governs the scope and enforceability of the patent.
Required Documents to File Patent in Bulgaria
A complete national phase filing in Bulgaria includes:
- Copy of the PCT Application: Automatically provided by WIPO; additional verification copies can be requested.
- Bulgarian Translation: Full translation of all application documents if not originally filed in Bulgarian.
- National Phase Entry Request: Formal request to enter the Bulgarian national phase.
- Power of Attorney (POA)
- Required for foreign applicants.
- A simple signed copy is sufficient.
- No legalization or notarization required in most cases.
- Assignment (if applicant ≠ inventor)
- A simple signed assignment document is acceptable.
- No legalization or apostille required unless specifically requested.
- Priority Documents: Only needed if not already transmitted through the PCT system.
- Sequence Listings: Required electronically if applicable.
Failure to provide required documents may result in refusal or withdrawal.
Bulgaria Patent Search and Examination Procedure – Overview
Bulgaria uses a hybrid examination system:
- Formal Examination: The BPO reviews forms, translations, and procedural matters.
- Mandatory Search Report: A search report is prepared by the Bulgarian Patent Office (or delegated authority) to identify prior art.
- Optional Substantive Examination
Bulgaria grants patents without full substantive examination unless:
- The applicant requests examination, or
- A third party requests examination
If substantive examination is requested:
- Patentability Search, inventive step, and industrial applicability are evaluated
- The procedure becomes more similar to a fully examined patent jurisdiction.
Applicants may choose whether to undertake substantive examination depending on enforcement and commercial strategy.
Examination Process and Office Actions
During prosecution, the Bulgarian Patent Office may issue:
Formal Office Actions
For missing translations, incomplete forms, or entitlement issues.
Search Report & Observations
The search report may be accompanied by non-binding observations regarding potential prior art issues.
Substantive Office Actions (if examination is requested)
These may address:
- Novelty objections
Inventive step issues
- Insufficient disclosure
- Unity of invention
- Claim clarity and support
Applicants must respond within set deadlines, usually one to three months, depending on the type of communication.
Deadline for Request for Examination
Substantive examination in Bulgaria is not automatic.
If the applicant wants a substantive examination:
A request must be filed within 13 months from the publication of the search report.
Failure to request examination:
- Results in a patent being granted without substantive evaluation.
- However, unexamined patents may be more vulnerable to invalidation in litigation
Publication Process and Legal Impact
Bulgarian patent applications are published:
18 months from the earliest priority date,
or earlier upon applicant’s request.
Publication:
- Establishes prior art
- Informs the public and competitors
- Begins the public record of the claimed invention
Publication does not create enforceable rights until a grant.
Grant Process and Enforceability
After formal requirements and search procedures are completed (and examination if requested):
- A grant decision is issued.
- The applicant pays the grant and publication fees.
- The granted patent is published in the Bulgarian Patent Bulletin.
A granted Bulgarian patent provides:
- Exclusive rights to prevent unauthorized production, use, import, or sale
- Ability to enforce in Bulgarian civil courts
- Possibility of injunctions, damages, and destruction of infringing goods
- Potential border enforcement via customs authorities
Bulgaria’s enforcement framework aligns with EU standards and provides strong judicial remedies.
Patent Validity Term
The term of a Bulgarian patent is:
20 years from the PCT filing date, subject to annual renewal fees.
Typical Time to Obtain a Patent in Bulgaria
Average processing time:
- 1.5 to 3 years for patents without substantive examination
- 3 to 5 years for patents with requested substantive examination
Timelines depend on Office backlog and applicant responsiveness.
Annuities and Maintenance Procedure
Maintenance fees (annuities):
- Begin from the third year
- Must be paid annually
- Have a six-month grace period with surcharge
- Increase progressively each year
Non-payment results in patent lapse.
Official Government Fees for Bulgaria Patent Filing (As Per the 2025 Schedule)
Filing & National Phase Entry Fees
| Fee Type | Amount (BGN) |
| National Phase Filing Fee | ~120 BGN |
| Each Additional Claim (above 10) | ~20 BGN |
| Priority Claim Fee (per claim) | ~20 BGN |
Bulgaria Patent Search Fees
| Fee Type | Amount (BGN) |
| Search Fee | ~500 BGN |
| Additional Search (if required) | ~300 BGN |
Substantive Examination Fees
| Fee Type | Amount (BGN) |
| Request for Substantive Examination | ~300 BGN |
| Examination of Amended Claims | ~80 BGN |
Grant & Publication Fees
| Fee Type | Amount (BGN) |
| Grant Fee | ~50 BGN |
| Publication Fee | ~40 BGN |
Fees increase steadily to reflect the growing commercial value of mature patents.
Utility Model Protection in Bulgaria
Bulgaria offers utility model protection, which:
- Provides a faster and simpler registration process
- Offers protection for up to 10 years
- Is ideal for mechanical innovations and incremental improvements
- Does not require substantive examination
Applicants may convert a patent application into a utility model, depending on strategy.
Bulgaria Patent Office & Official Website
Official Website: Bulgarian Patent Office
