Regulation (EU) n. 1303/2013 of the European Parliament and of the Council of 17 December 2013, art. 2, point 36): "irregularity: any breach of Union or national law relating to its application, resulting from an action or omission by an economic operator involved in the implementation of the ESI funds that it has or may have as a result prejudice to the Union budget by imputing undue expenditure to the Union budget ".

Convention drawn up on the basis of Article K.3 of the Treaty on European Union concerning the protection of the European Communities' financial interests, art. 1 "General provisions", par. 1, lett. a) (see OJ C 316 of 11/27/1995, p. 49): "1. For the purposes of this agreement, it constitutes fraud that affects the financial interests of the European Communities: ... any related intentional action or omission: - to the use or presentation of false, inaccurate or incomplete statements or documents which result in the receipt or unlawful retention of funds from the general budget of the European Communities or from the budgets managed by the European Communities or on their behalf; - the failure to communicate information in violation of a specific obligation which has the same effect; - the distraction of such funds for purposes other than those for which they were initially granted ".

The Code of Conduct for Employees of the Puglia Region approved with D.G.R. n. 1423/2014, in accordance with the Code of conduct for public employees approved with D.P.R. n. 62/2013 in compliance with the l. n. 190/2012, cd. law Severino, places the obligation for the employee to inform in writing, at the time of assignment to the office / service / regional structure, the manager of reference of "all relations, also through a third party, collaboration or consultancy, however denominated, with private subjects, including non-profit companies or bodies, in any way paid or free of charge, that the same has or has had in the last three years [...] "(see art. 6, par. 1.
The Code of Conduct for employees of the Puglia Region also places an obligation on all employees to refrain from "making decisions or carrying out activities related to their duties in situations of conflict, even potential, of interests in which personal interests are involved, of the spouse, cohabitants, relatives, relatives up to the second degree. The conflict may concern interests of any nature, including non-patrimonial ones, such as those deriving from the intention of wanting to support political, trade union or hierarchical superiors. Conflicts in which the financial and non-financial interests of an employee can conflict or interfere with the public interest related to the activities and functions assigned to it"(see Article 6, paragraph 1). The obligation to abstain is also extended to decisions and activities that may involve the interests of other subjects:
"1. [...]
a) persons with whom the employee has usual attendance relationships;
b) subjects or organizations with which he or his spouse has a pending cause or serious enmity or significant credit or debt relationships;
c) subjects or organizations of which he is guardian, curator, attorney or agent;
d) bodies, associations, including unrecognized ones, committees, companies or establishments of which he is director or manager, manager or in which he holds corporate and / or representative offices.
2. The employee abstains in any other case
which there are serious reasons of opportunity and convenience"(see art. 7, paragraphs 1 and 2).

Definition of conflict of interests in the European Union
As reported by the Practical Guide for Executives drawn up by OLAF "Identification of conflicts of interest in tender procedures in the framework of structural actions" (see Chapter 1 "Definitions"), the notion of "conflict of interest" is not harmonized at European Union level. Although penal measures applicable to conflicts of interest exist in all Member States, some of them have not introduced a definition expressed in their legal system.

The law of the European Union defines the conflict of interest for the purposes of the implementation of the general budget of the Union under the Reg. (EU) n. 1046/2018 which, in art. 61, par. 3 establishes: "[...] there is a conflict of interest when the impartial and objective exercise of the functions of a financial agent or of another person is [...] compromised by family, emotional, affinity reasons political or national interest, economic interest or any other direct or indirect personal interest". A conflict of interest therefore arises when a person could have the opportunity to put their private interests before their professional obligations.

Definition of OECD conflict of interest
The Organization for Economic Co-operation and Development (OECD) has proposed the following definition: "A conflict of interest" implies a conflict between the public mission and the private interests of a public official, in which the latter has a title private interests that could unduly influence the fulfillment of its public obligations and responsibilities"(see Managing Conflict of Interest in the Public Service, OECD GUIDELINES AND COUNTRY EXPERIENCES, pages 24-25).
The OECD has also identified three types of conflicts of interest:
- a real conflict of interest implies a conflict between the public mission and the private interests of a public official, in which the latter has private interests that could unduly influence
on the performance of its public obligations and responsibilities;
- an apparent conflict of interest can be said to exist when it seems that the private interests of a public official may unduly influence the fulfillment of his obligations, but, in fact, this is not the case;
- a potential conflict of interest occurs when a public official has private interests that could give rise to a conflict of interest if the official were to take on specific (ie conflicting) official responsibilities in the future.