Exclusion of evidence of oral agreement

Reference: The Indian Evidence Act
Section 92

When the terms of any such contract, grantor other disposition of property, or any matter required by law to be reduced to the form of a document have been proved according to the last Section, no evidence of any oral agreement of statement shall be admitted, as between the parties to any such instrument or their representatives in interest, for purpose of contradicting, varying, adding to, or subtracting from, its terms
Proviso (1) – Any fact may be proved which would invalidate any document, or which would entitle any person to any decree or order relating thereto; such as fraud, intimidation, illegality, want of due execution, want of capacity in any contracting party, want or failure] of consideration, or mistake in fact or law.
Proviso (2) – The existence of any separate oral agreement as to any matter on which a document is silent, and which is not inconsistent with its terms, may be proved. In considering whether or not this proviso applies, the Court shall have regard to the degree of formality of the document.
Proviso (3) – The existence of any separate oral agreement, constituting a condition precedent to the attaching of any obligation under any such contract, grant or disposition of property, may be proved.
Proviso (4) – The existence of any distinct subsequent oral agreement to rescind or modify any such contract, grant or disposition of property, may be proved, except in cases in which such contract grant or disposition of property is by law required to be in writing, or has been registered according to the law in force for the time being as to the registration of documents.
Proviso (5) – Any usage or custom by which incidents not expressly mentioned in any contract are usually annexed to contracts of that description, may be proved provided that the annexing of such incident would not be repugnant to, or inconsistent with the express terms of the contract.
Proviso (6) – Any fact may be proved which shows in what manner the language of a document is related to existing facts.

This Section supplements Section 91 as it would be pointless to make evidence of a document (other than the document itself) inadmissible if it contradicting, varying, adding to, or subtracting from its terms was permitted.
Sections 91 and 92 are, as the Supreme Court pointed out in Roop Kumar v. Mohan Thedani, 2003, different in some material particulars. It was held that ‘Section 91 aplies to all documents, whether they purport to dispose of rights or not whereas Section 92 applies to documents which can be described as dispositive. Section 91 applies to documents which are both bilateral and unilateral, unlike Section 92 whose application is confined to bilateral agreements’.
Proviso 1 deals with agreements whose validity has been impeached (See Illustrations d and e) and should be read with Section 31 of the Specific Relief Act.

Section 92 applies only when there is no infirmity in the document; facts which invalidate a document can be proved by oral evidence.
Proviso 2 deals with matters on which the agreement is silent. (See Illustrations f, g and h) It is under this proviso that oral evidence is admissible on matters which the document does not speak of although the evidence given cannot be inconsistent with the written terms of the agreement. Also, the Court considers the formality of the document which deciding whether or not the proviso applies i.e. a Court may permit the missing links in a document drafted by a layman to be filled in by oral evidence but may not do so if the document in question has been drafted by a team of lawyers: in such a case, the Court may conclude that what has been left blank has been deliberately left blank.
Proviso 3 deals with conditions precedent to obligation. For example, Section 144 of the Contract Act which deals with guarantees says ‘where a person gives a guarantee upon a contract that a creditor shall not act upon it till another person has joined in it as co-surety, the guarantee is not valid if that other person does not join. Here, the agreement that the person would be under no obligation until a co-surety joined in the guarantee may be proved.