Porter v. Harrington
Supreme Judicial Court of Massachusetts 159 N.E. 530 (Mass. 1928)


Harrington agreed to sell Porter a couple of lots. $60 was to be paid up front, and the remaining balance was payable at a rate of $10 per month.

  • For the next several years, payments were basically made here and there, sometimes more than the $10 required.
  • Eventually, Harrington exercised an option in K that allowed him to terminate the agreement if Porter failed to keep up with the payments. He also kept what was paid as liquidated damages.
  • After Porter unsuccessfully offered to pay off the remaining balance, he sued for specific performance.


Lower court ruled in favor of Porter.


Whether a reasonable person would construe Harrington’s acceptance of Porter’s late payments as a waiver of the condition of timely payments.


Yes. Affirmed.


  • The court found an implied waiver (“a waiver evidenced by a party’s decisive, unequivocal conduct reasonably inferring the intent to waive”).
  • Harrington, by a course of dealings lasting over several years, constantly accepted delayed payments without objection, so it would be unconscionable to permit him to the insist upon strict performance of the contract.