This section is from the book "The Law Of Contracts", by William Herbert Page. Also available from Amazon: Commercial Contracts: A Practical Guide to Deals, Contracts, Agreements and Promises.
The parol-evidence rule which forbids the introduction of evidence of prior or contemporaneous oral negotiations to vary or contradict the terms of a written contract, has no application to cases in which it is sought to prove by oral evidence a new contract which was made after the original written contract was made. Contracts which are in writing merely because the parties thereto chose to reduce them to writing offer no technical difficulties to subsequent oral modifications. Accordingly, the parol-evidence rule does not prevent the parties to a written contract, not under seal, and not required by law to be in writing or to be proved by writing, from making subsequent oral modifications of its terms.1 A subsequent oral settlement making an account stated;2 a subsequent extension of time;3 a subsequent agreement that a policy, the premium for which by its terms was payable in advance, should take effect at once, the insurer holding the policy until the premium was paid;4 to deliver a note to an agent of the adversary party;5 or providing that a note already indorsed should be received as security and not as payment,6 may all be used as modifications of prior written contracts.
8 Wallace v. Babcock, 93 Wash. 392, 160 Pac. 1041.
9 Levy v. Levy, 139 La. 274, 71 So. 507.
10 Levy v. Levy, 139 La. 274, 71 So. 507.
11 Morgan v. Child, 47 Utah 417, 165 Pac. 451.
12Moll v. Roth Co., 77 Or. 593, 152 Pac. 235.
1 United States. Wood v. Ft. Wayne, 119 U. S. 312, 30 L. ed. 416; The Sappho, 94 Fed. 545, 36 C. C. A. 395 [reversing, 89 Fed. 366]; Pecos Valley Bank v. Evans-Snider-Buel Co., 107 Fed. 654, 46 C. C. A. 534.
Alabama. Hartford, etc., Co. v. At-talla, 119 Ala. 59, 54 So. 845; Andrews v. Tucker, 127 Ala. 602, 29 So. 34.
California. Katz v. Bedford, 77 Cal. 319, 1 L. R. A. 826, 19 Pac. 523.
Colorado. Hurlburt v. Dusenbery, 26 Colo. 240, 57 Pac. 860.
Florida. Gunby v. Drew, 45 Fla. 350, 34 So. 305.
Illinois. Palmer v. Bennett, 96 I1L App. 281; Chicago, etc, Co. v. Moran, 187 111. 316, 58 N. E. 335 [affirming, 85 111. App. 543].
Indiana. Toledo, etc., Ry. v. Levy, 127 Ind. 168, 26 N. E. 773.
Iowa. Lamb's Estate v. Morrow, 140 Ia. 89, 18 L. R. A. (N.S.) 226, 117 N. W. 1118; Lefebure v. Lord, - Ia. - , 167 N. W. 651.
Kentucky. John King Co. v. Louisville & N. R. Co., 131 Ky. 46, 114 S. W. 308 [rehearing denied, John King Co.
A subsequent agreement by a vendor, on valuable consideration, to give different warranties from those in the original written contract of sale, can be enforced.7 The subsequent modification can be most readily shown after it has been performed in full.8 By statute, in some jurisdictions, subsequent oral modifications of written contracts can be enforced only when partly performed. If purely executory they are unenforceable.9 The oral modification is not partly performed unless something has been done which the party performing was not bound to do under the original contract.10 A statute which requires performance of an oral alteration of a written contract is held to have no application to an oral contract which is intended by the parties as a substitute for the original written contract.11 v. Louisville & N. R. Co., 116 S. W. 1201].
Massachusetts. Bartlett v. Stanch-field, 148 Mass. 394, 2 L. R. A. 625, 10 N. E. 549.
Michigan. Moore v. Locomotive Works. 14 Mich. 266; Mouat v. Barn-let, 123 Mich. 345, 82 N. W. 74.
Minnesota. Hagstrom v. McDougall, 131 Minn. 589, 1.55 N. W. 391.
Missouri. Conrad v. Fisher, 37 Mo. App. 352, 8L.R.A. 147.
Nebraska. Strahl v. Western Grocer Co. (Neb.), 98 N. W. 1043.
North Carolina. Harris v. Murphy, 119 N. Car. 34, 56 Am. St. Rep. 656, 25 S. £. 708; Acme Manufacturing Co. v. McCormick, 175 N. Car. 277, 95 S. E. 555.
North Dakota. Wadge v. Kittleson, 12 N. D. 452, 97 N. W. 856; Quinlivan v. Dennstedt Land Co., - N. D. - , 168 N. W. 51.
Oregon. Cline v. Shehl, 43 Or. 372, 73 Pac. 12.
Pennsylvania. Cunningham v. Church, 159 Pa. St. 620, 28 Atl. 490; Achenbach v. Stoddard, 253 Pa. St. 338, 98 Atl. 604.
Tennessee. Chicago, etc., Co. v. Barry (Tenn. Ch. App.), 52 S. W. 451.
Virginia. J. P. Houck Tanning Co. v. Clinedinst, 118 Va. 131, 86 S. E. 851.
Washington. Carstens v. Earles, 26 Wash. 676, 67 Pac. 404; Andersonian Investment Co. v. Wade, - Wash. - , 184 Pac. 327.
Wisconsin. Wisconsin Sulphite Fibre Co. v. D. K. Jeffris Lumber Co., 132 Wis. 1, 111 N. W. 237.
See ch. LXIX.
2Krueger v. Dodge, 15 S. D. 159, 87 N. W. 965.
3 Bannon v. Aultman, 80 Wis. 307, 27 Am. St. Rep. 37, 49 N. W. 967.
4 Prudential Ins. Co. v. Sullivan, 27 Ind. App. 30, 59 N. E. 873.
5 Stokes v. Polley, 164 N. Y. 266, 68 N. E. 133.
6 Willow River Lumber Co. v. Furniture Co.. 102 Wis. 636, 78 N. W. 762.
7 McCormick Harvesting Mach. Co. v. Hiatt (Neb.), 95 N. W. 627.
8 Town v. Jepson, 133 Mich. 673, 95 N. W. 742.
9 Thompson v. Gorner, 104 Cal. 168, 43 Am. St. Rep. 105, 37 Pac. 900; Mackenzie v. Hodgkin, 126 Cal. 691, 77 Am. St. Rep. 209, 59 Pac. 36; Henehan v. Hart, 127 Cal. 656, 60 Pac. 426; Ar-mington v. Stelle, 27 Mont. 13, 69 Pae. 115.
If the original contract is in writing, and it is sought to modify such contract by an oral agreement or to discharge it, it must be shown that the oral agreement was made subsequent to the written contract, since if it was entered into at substantially the same time, the oral contract is unenforceable by reason of the parol-evidence rule.12 If a written contract for building a house does not require the contractor to paper the walls, an oral agreement entered into at substantially the same time, providing that the contractor shall paper the walls, is unenforceable.13
Under pretext of showing an oral contract entered into subsequently to the written contract, the party who wishes to show such oral contract can not show oral representations made by the adversary party before such written agreement was made.14