PCT Application



PCT application makes it possible for patent applicants or inventors to file single centralised international application in one patent office (receiving office), i.e. the Bulgarian Patent Office (BPO), European Patent Office (EPO) or directly with WIPO, in one language, such application having effect in all 152 PCT Member States designated by the applicant in the international application.

PCT Application procedure and costs - KTpatent.com

Hence the initial transaction costs of submitting separate patent applications to each patent office are reduced and postponed. Moreover, the PCT provides at least 18 additional months on top of the 12 month priority period, in which applicants can explore the commercial potential of their product in various countries and decide where to seek patent protection. Payment of the fees and translation costs associated with national patent applications is thus delayed. The PCT is the main aspect of companies` patent strategies and is widely used by applicants to keep their options open for as long as possible.


Additionally, an international application (PCT application) shall be subject to international search resulting in an International Search Report with the relevant state of the art cited therein, as well as a Written Opinion of the International Search Authority on the patentability of the invention.  The results of the International Search Report make it possible for the applicant to evaluate the chances for the grant of national patents and commercial success of the invention, while the application is still pending in the international phase and the substantial costs are postponed until the national/regional phases. 


PCT is a closed patent filing system, which practically means that only applicants who are residents, nationals or have a place of business in at least on of  all PCT contracting states may file international patent application. An international application may have several applicants, but at least one of them must be a resident of a PCT contracting state.


National law of each PCT contracting state prescribes the requirements that a PCT applicant be represented by a local agent or a patent attorney. Most of the countries do not require an agent or patent attorney for applicants resident in the state concerned. However, all PCT applicants are strongly advised to appoint an experienced patent attorney who can conduct the patent drafting, filing and prosecution of a PCT application in the most professional, legally binding and efficient way. EQE qualified European Patent Attorney is the best option for all applicants from EPC contracting states.


The PCT application, however, does not lead to an “international patent”. Depending on the respective country, the applicant has to select national/regional patent offices of the countries or regions, where patent protection is finally desired, within 30 or 31 months after the priority date of the international application. This is the so-called “PCT National Phase”, which in fact is the phase of granting a patent for invention. Each selected national/ regional patent office then independently decides on the patentability of the international patent application in the respective country/region. Some countries also allow protection by utility model upon entry into national phase instead of the classic patent.


The entry into a national phase requires payment at the designated and elected offices of the prescribed national (regional) fees, submission of a translation of the international patent specification into the respective language, complying with all requirements under the national patent law in each desired country, as well as appointing national patent attorneys in each country to represent the applicants before the respective national patent offices.


For the purpose of entering a PCT national phase in Bulgaria, the applicant shall file the international application with the Bulgarian Patent Office (BPO) within thirty one (31) months from the filing date, or if priority has been claimed, then from the earliest priority date of the PCT application, pay all the respective fees under national law and translate the patent specification (the description and the claims) into Bulgarian language.


Under the Bulgarian Patent Law, the PCT applicants willing to enter Bulgarian PCT national phase, may seek protection for a national Bulgarian Patent and/or Utility model registration in Bulgaria in parallel with the national patent or instead it respectively.


Foreign applicants (not being Bulgarian nationals or companies) are obliged to appoint a qualified Bulgarian Patent Attorney to represent them in the national phase before the Bulgarian Patent Office (BPO). However, the Bulgarian applicants are also strongly recommended to hire an experienced Bulgarian Patent Attorney. 


For the purpose of entering a EURO-PCT phase, the applicant shall file the international application with the European Patent Office (EPO) within thirty one (31) months from the filing date, or if priority has been claimed, then from the earliest priority date of the PCT application. Upon entry into EURO-PCT phase, its EPO’s responsibility to examine the PCT application and decide on patentability criteria concerning the grant of a European Patent


Additional series of “steps”, in order to fulfil the paramount amount of requirements, shall be performed as well. The minimum requirements to be met can be summarised as follows: supply the translation into English, French or German if the Euro-PCT application was not published in one of the EPO’s official languages; specify the application documents; pay the EP filing fee, designation and search fees (if applicable); file the request for examination and pay the examination fee; pay the patent renewal fees for the third year (if applicable).


In general, PCT applicants need not be represented by professional representatives in the proceedings before the EPO provided they are nationals or have place of business within the territory of one of the EPC contracting states. Otherwise, all non-resident applicants must be represented by a professional representative and act through him in all proceedings before EPO. Although not required by law in the first case, representation is also recommended for both resident and non-resident applicants, preferably by appointing an EQE qualified European Patent Attorney. Professional handling of the case is in the interest of the PCT applicant, ensuring that he achieves the desired goal and procedure before EPO is conducted efficiently.


* REMARKS: 1) This is an approximate time scale calculated as from the EP filing date; 2) Attorney fees are not included and all official fees are tentative

Filing of PCT Application


A PCT application must contain: a request for International patent application, a description of the invention, disclosing the invention in a manner sufficiently clear and complete for it to be carried out by a person skilled in the art; at least one or more patent claims, defining the scope of protection; any drawings referred to in the description or patent claims; and an abstract. The application must be filed with the applicant's receiving IP Office or WIPO. The Official fees due at the filing stage are filing and search fees which amount to about 2950 EUR. A surcharge is also levied for each page above 30 which is 13 EUR. Almost every Receiving Office also collects a transmittal fee which is fixed by each office. For the Bulgarian Patent Office this fee is 42 EUR and for EPO is 130 EUR. The international filing fee may be reduced in some cases if the applicant(s) satisfy certain requirements prescribed by PCT.

International Search, issuing International Search Report and Opinion on patentability


The international search report is an important element of the PCT procedure as it lists all prior art documents available to the International Search Authority that are considered relevant for assessing novelty and inventive step. The search report is based on the patent claims but also takes into account the description and any drawings. In addition to the search report, an initial non-binding opinion on patentability is issued, namely whether the claimed invention and the application meet the requirements of PCT. Both documents are then sent to the applicant or his Patent Attorney, who may evaluate the results and reasonably decide whether to proceed further with the international and subsequent national patent grant procedures. In practice, the search report and opinion give the applicant a first impression of his chances of obtaining a patent on his invention.


+- 18 MONTHS

After receipt of the international search report the applicant has one opportunity to amend ONLY his claims in view of the search report. Other parts of the international application may not be amended in this stage of procedure.

Publication of the PCT Application


The international PCT application is published promptly after expiration of 18 months from the filing date or if priority is claimed from the earliest priority date. The application is then made available on the Internet. From the date of publication, a PCT application may confer provisional protection of the invention in the countries designated in the application as published, provided the national requirements, such as translation and publication of the patent claims, are fulfilled.

Request for Supplementary International Search (SIS) - (optional)


The applicants have the option of filing a request for Supplementary International Search and where another International Search Authority (ISA) will conduct it independently from the one that carried out the main international search. The aim of this option is to find out prior art which was not found during the main international search, e.g. due to language limitations. The Supplementary International Search is subject to payment of a fee which is prescribed by each search authority independently.

Demand for International Preliminary Examination - (optional)


The applicant also has the option to have a preliminary examination being carried out by International Preliminary Examination Authority (IPEA) which draws up an International Preliminary Report on Patentability (IPRP). The Report provides a preliminary non-binding opinion on the novelty, presence of inventive step and industrial applicability of the invention. It gives the applicant a second impression of the patentability of the invention, on which he may decide whether or not to enter national or regional phases. During this optional examination, the applicant has a second opportunity to amend the claims and a first opportunity to amend the description and any drawings. The Demand is subject to payment of a fee for preliminary examination, which is prescribed by each IPEA independently.

Entry into National / Regional phases

30 / 31 MONTHS

At the 30/31 months from the filing, or where priority has been claimed from the earliest priority date, the International Phase ends. The international application then splits into national or regional patent applications by entering enter national or regional phases before the national or regional patent offices where protections is contemplated. Each application is then independently prosecuted and processed by each IP office under the national or regional patent law respectively. The costs for national/regional entry are relatively high because of the significant number of fees to be paid to each national or regional office, the translations of the application to be made and patent attorney's service fees. However, the overall costs mainly depend on the number of countries of interest. The 30/31 month period is absolute deadline for performing the acts for entry into national/regional phases. If the applicant does not perform these acts within the prescribed time limit by each IP Office of interest, the international patent application will loose the effect of a national application in respect of that Office and protection of the invention in this state would be impossible to be acquired.

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