LEGAL PRINCIPLE: EVIDENCE LAW — Documentary Evidence — Parol Evidence Rule — Exclusion of Extrinsic Evidence to Vary Written Contract — Section 132(1) of Evidence Act
PRINCIPLE STATEMENT
Where parties have embodied the terms of their contract in a written document, extrinsic evidence is not admissible to add to, vary, subtract from or contradict the terms of the written instrument. This applies to guarantees, leases, contracts of sale, and other written instruments.
RATIO DECIDENDI (SOURCE)
Per Onu, JSC, in Union Bank of Nigeria Limited v. Nwaokolo (1995) NLC-2171991(SC) at pp. 5–6; Paras. D–A.
"Where the parties have embodied the terms of their contract in a written document, extrinsic evidence is not admissible to add to, vary, subtract from or contradict the terms of the written instrument. The general rule is that where the intention of the parties has been reduced to writing, it is not permissible to adduce extrinsic evidence, whether oral or contained in writings such as instructions, drafts, preliminary agreements, either to show that intention or to contradict, vary or add to the terms of the document. This principle applies to guarantees, leases, contracts of sale, and other written instruments."
EXPLANATION / SCOPE
The parol evidence rule excludes extrinsic evidence to vary written contracts. The written document is the sole evidence of the agreement. The principle applies to all written instruments. The rule ensures certainty and prevents fraud. Exceptions include evidence of custom, usage, or collateral agreements. The court will enforce the written terms.