When a document recites that it is “signed as a sealed instrument” or “signed under seal” there is a presumption that it was supported by adequate consideration. But can such a document be modified by another agreement which is not under seal? Can it be modified by an oral agreement?
It can. An unsealed agreement, including an oral agreement, supported by adequate consideration, can modify a sealed instrument. Numerous Massachusetts cases support this conclusion. In L.W. Severance & Sons, Inc. v. Angley, 332 Mass. 432, 439 (1955) the Court stated:
Finally the plaintiff argues that as matter of law the modification of the original contract relied upon by the defendants was not good because a contract under seal cannot be modified by a subsequent oral agreement. This is not the law and the cases relied upon by the plaintiff do not sustain that proposition.
Similarly, according to the Court in Cohen v. Homonoff, 311 Mass. 374, 376 (1942), “it has long been settled in this Commonwealth that a written contract under seal, before breach, may be varied by a subsequent oral agreement made upon a legal consideration.” See also Elm Farm Foods Co. v. Cifrino, 328 Mass. 549, 556 (1952); Lampasono v. Capriotti, 296 Mass. 34, 37-38 (1936) (“Even a sealed contract may be modified orally”); Commonwealth Investment Co. v. Fellsway Motor Mart, Inc., 294 Mass. 306, 313-14 (1936); Citizens Bank of Massachusetts v. Milligan, 2006 WL 416963, *3 (Mass. Super. 2/1/06) (“Massachusetts law provides that a sealed instrument can be modified by an unsealed instrument”).
Thus, while sealed instruments have other unique characteristics, where modification is concerned they are treated like any other contract.