Defendant argues that the trial judge erroneously excluded evidence which would have tended to show that the plaintiff had extended the time for payment under the installment contract to the fifteenth of each month.
[1] All the evidence shows that the sale and delivery of this automobile took place in Tennessee. The contract in question should be governed by the laws of Tennessee unless contrary to the public policy of this State. Motor Co. v. Wood, 237 N.C. 318, 75 S.E. 2d 312; Roomy v. Insurance Co., 256 N.C. 318, 123 S.E. 2d 817. This is in accordance with the agreement of the parties.
[2] The contract entered into by the defendant contains the following language: “This contract constitutes the entire agreement between Purchaser and Seller and no modification of any of the terms and conditions herein shall be valid in any event, and Purchaser expressly waives the right to rely thereon, unless made in writing duly executed by Seller.” It is clear that under Tennessee law a written *253contract may be modified by a parol agreement after it is made. See Co-Operative Stores Co. v. United States Fidelity & G. Co., 137 Tenn. 609, 195 S.W. 177, where the Tennessee Supreme Court stated:
“A written contract may be changed by parol, and this although it stipulate that it shall only be changed in writing, for the obvious reason that men cannot tie their hands or bind their wills so as to disable them from making any contract allowed by law, and in any mode in which it may be entered into. . . . A written bargain is of no higher legal degree than a parol one. Either may vary or discharge the other, and there can be no more force in an agreement in writing not to agree by parol than in a parol agreement not to agree in writing. Every such agreement is ended by the new one which contradicts it.” (citations omitted.)
This same rule prevails in North Carolina. “The exclusion of parol evidence on the theory that it is inadmissible to amend, vary or contradict a written instrument has no application to subsequent agreements which change or modify the original contract.” Whitehurst v. FCX Fruit and Vegetable Service, 224 N.C. 628, 32 S.E. 2d 34.
[3-5] The only testimony in this record concerning a subsequent agreement to change the date for making payments was elicited from the defendant out of the presence of the jury. Defendant stated that an official of Ford Motor Credit Company told him that he could make payments by the fifteenth of each month. Although the above evidence was admissible under the rule that a written contract may be changed by a subsequent oral agreement, we do not think its exclusion was prejudicial. Under Tennessee and North Carolina law the defendant had the burden of proving the subsequent modification to the written contract. Balderacchi v. Ruth, 36 Tenn. App. 421, 256 S.W. 2d 390; Russell v. Hardwood Co., 200 N.C. 210, 156 S.E. 492. Evidence of an oral agreement which modifies a written contract should be clear and convincing. Wertheimer v. Byrd, 278 Minn. 150, 153 N.W. 2d 252. We do not think the statement that “[an official of Ford Motor Credit Company] said that it would be acceptible (sic) to make my payment between the 10th and 15th of each month — until the 15th of each month” satisfies this requirement. The evidence, if allowed, would not be sufficient for submission to the jury.
[6, 7] Defendant next argues that the plaintiff should not have been allowed to repossess the automobile because late payments were consistently accepted, late charges levied, and that he had not been notified that it was necessary to make payments on the due date specified in the contract. We need not decide whether under certain *254situations a creditor may waive the right to receive payments at the time specified in the installment contract. We need only say that under the facts now before us, we do not think such a waiver has' been shown. Notices mailed to the defendant during August and September of 1967 state that the installments were due on the seventh of each month. This is inconsistent with defendant’s argument that he had not been notified that it was necessary to make payments on the date specified. “[Modification of an existing contract cannot arise from an ambiguous course of dealing between the parties from which diverse inferences might reasonably be drawn as to whether the contract remained in its original form or was changed.” Balderacchi v. Ruth, supra. This rule applied to the present case leads to a result which is in accord with sound policy. Should the rule be that the mere acceptance of late payments waives the right to receive subsequent payments on time, financial institutions would have to take the position that it would never be prudent to accept late payments. Flexibility would be severely hampered. This is not to say that acceptance of late payments along with evidence of unconscionable or improper actions on the part of a financial institution would not constitute a waiver. Such a situation is not before us. Moreover, the contract in the present case provides that “Waiver by Seller of any default shall not be deemed a waiver of any other default.” We do not agree that plaintiff has waived the right to demand that payments be made according to the provisions of the contract.
Evidence offered by plaintiff and defendant shows that the defendant violated other provisions of this agreement by bringing the automobile to North Carolina without written permission from the plaintiff, and by declaring bankruptcy. Since these actions were not relied on by the plaintiff as grounds for the repossession of the automobile, we do not discuss them. The undisputed evidence shows that the October 1967 payment has never been made by the defendant.
The judgment below is
Affirmed.
Campbell and Beooic, JJ., concur.