Complaint :

“Complaint” means any allegation made orally or in writing to a Magistrate, with a view to his taking action under this Code, that some person, whether known or unknown, has committed an offence, but it does not include a police report. [Section 2(d)]

However, a report made by the police officer in a case which discloses after investigation, the commission of a non-cognizable offence shall be deemed to be a complaint, and the police officer making the report as a complainant. In general a complaint into an offence can be filed by any person except in cases of offences relating to marriage, defamation and offences mentioned under Sections 195 and 197.

A complaint in a criminal case is what a plaint is in a civil case. The requisites of a complaint are:

(i) an oral or a written allegation;

(ii) some person known or unknown has committed an offence;

(iii) it must be made to a magistrate; and

(iv) it must be made with the object that he should take action.

There is no particular format of a complaint. A petition addressed to the Magistrate containing an allegation that an offence has been committed, and ending with a prayer that the culprit be suitably dealt with is a complaint. (Mohd. Yousuf v. Afaq Jahan, AIR 2006 SC 705).

Police report is expressly excluded from the definition of complaint but the explanation to Section 2(d) makes it clear that such report shall be deemed to be a complaint where after investigation it discloses commission of a non-cognizable offence. Police report means a report forwarded by a police officer to a Magistrate under Subsection (2) of Section 173.