"Counsel for the Credit Union pointed to the case of John Burrows Ltd et al v Subsurface Surveys Ltd [1968] SCR 607, followed in Ireland by Creative Press Limited v Harman [1973] IR 313. It was a case of a promise permitting the maker, at his own discretion, to make payment on account of principal from time to time in advance of maturity. Counsel contended that in such a case interest could not be calculated without extraneous information concerning possible prepayments. Nonetheless, the instrument was held to be a promissory note.
That case is not of any assistance to the Credit Union. It was decided on the basis that the instrument under consideration was a promissory note because it created no contingency and complied with the definition given in s 176(1) of the Act. ...
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The case at bar has to do with the certainty of the amount, not the contingency of the promise.
The certainty of the amount payable was not discussed in the judgment of this court in the John Burrows case, either as to principal or interest, simply because it was not considered to be in issue.
If the maker of such a note, as was considered in that case, pays part of the principal prior to maturity, he pro tanto discharges it and would be wise to have the partial discharge acknowledged in writing on the instrument. He would otherwise run the risk of paying twice should the note be delivered to a holder in due course, who would have no reason to presume that the maker has availed himself of the prepayment privilege.
With respect to the time of payment, such a note is even more certain than a note payable on demand since it states a definite date beyond which it cannot run. There is no uncertainty as to the amount of principal payable: insofar as a holder in due course is concerned, the full amount is payable, less the amount of such prepayments as may have been acknowledged in writing on the instrument. As in the case of a note payable on demand, the amount of interest can be calculated at all times on the basis of the full amount of the principal or of what remains of it on the face of the document. It is true that a new prepayment on account of principal might be forthcoming and this creates a degree of uncertainty relating to the exact amount of interest that will ultimately be payable. But such uncertainty is of the same nature as the uncertainty of the amount of interest ultimately payable in the case of a note payable on demand, although it depends on the option of the maker, not the holder.
The note considered in the John Burrows case was thus sufficiently certain on its face with respect to its essential elements to comply with the requirements of negotiability."