In order to obtain a filing date, a patent application for an invention must contain:

1. Patent application for an invention with the title of the invention for which the patent is sought and the identification data of the applicant.
2. Description of the invention disclosing its essence.

In order to initiate the procedure in the Patent Office, in addition to the obligatory documents, the application must also contain:

• Declaration of actual inventors, which applies where the applicant is different from the inventor.
• Declaration of license readiness, which is applied when filing a patent application, if the applicant is ready to grant a license. When the application is submitted with such a declaration, the applicant receives a 50% discount when paying fees.
• Priority certificate when an earlier convention priority has been declared in the application.
• Power of attorney of an industrial property representative, when authorized.
• Declaration on the organization of budget support, when the applicant is such an organization.
• Patent claims, abstract and drawings, if not attached to the description when filing the application.
• Declaration for a micro and small enterprise under the Small and Medium Enterprises Act, when the applicant is such an enterprise, according to the model of the Executive Agency for Promotion of Small and Medium Enterprises; in this case the applicant enjoys a 50% discount when paying the fees for application, expertise and appeal against the decision of the expertise.
• Document for paid application fees, for verification of the formal requirements, for preliminary expertise and admissibility of the legal protection, for claims - when their number is over ten, and for claimed priorities, the amount of which is determined in the Tariff for fees collected by the Patent Office of the Republic of Bulgaria.

The necessary documents, as well as detailed instructions for the procedure for granting a patent can be found on the website of the Patent Office.

The patent application is filed directly with the Patent Office, by fax, e-mail, postal operator or electronically through the Patent Office Portal.

Ideas are not subject to patent protection. When compiling the description, it is necessary to clearly and fully disclose the technical solution to a problem.

Methods of treatment of humans or animals by therapy or surgery, as well as diagnostic methods used in humans or animals, are not patentable. A patent or utility model may be granted that relates to a product, e.g. a medicament, device, etc.

Computer programs and web pages are not patentable.

The composition of each food product and the devices used in this production can be protected by a patent for an invention or by registration of a utility model. Food production methods can be protected by a patent for an invention. For this purpose it is necessary to apply for a patent for an invention or for registration of a utility model with the Patent Office.

For all actions related to the filing of an application, the proceedings in the Patent Office, the issuance of a protection document and the publications, fees are paid according to the current Tariff of Fees, which are collected by the Patent Office of the Republic of Bulgaria.

Bibliographic information on the application for invention shall be published in the Official Bulletin of the Patent Office immediately after the expiration of 18 months from the date of its filing or the priority date. After the publication in the bulletin, the documents for which the publication was made are available in the Central Patent Library, after requesting.

Changes to the application may be made at any time in the patent procedure, provided that they do not go beyond the original disclosure and after payment of the relevant fee.

The term of validity of the issued patent and 20 years from the date of filing the application. The validity of the patent is maintained by paying a fee for the respective patent year in the previous patent year. Fees for maintaining the validity of the patent for the period from the filing of the application to the issuance of the patent shall be paid simultaneously with the fees are the issuance and publication of the grant.  If the patent owner has failed to pay the respective patent year in time, he has the opportunity within 6 months from its expiration to pay the due fee with a fine, which will be able to maintain the validity of the patent. If this term is missed, the owner has the opportunity within an additional 6 months to renew the patent by paying the relevant fee in double amount and in addition it is necessary to pay an additional fixed amount for the restoration of the patent.

The due fees can be paid at the cash desk in the Office, by bank transfer, by standard bank transfer, as well as by electronic banking. The bank account is indicated on the website of the Office.

The issuance of a duplicate is part of the administrative services provided by the Patent Office. The request shall be submitted in free form or according to a sample of the Patent Office by the holder of the registration, and a respective fee shall be paid according to the Tariff for fees collected by the Patent Office of the Republic of Bulgaria.

The issued security document is valid only on the territory of the country in which it was issued, ie. in this case only on the territory of Bulgaria.

If the applicant's interests require protection of an invention abroad, he may apply using the Patent Cooperation Treaty (PCT) system or the European patent system.

Detailed information on the procedure for granting a European patent is published on the EPO website, and on the procedure for filing an international application and opening a national phase under the PCT - on the website of the World Intellectual Property Organization (WIPO).