Is a promissory note payable at 14.25% per annum until paid?

I limit my finding to July 19, 1982, because the next question that arises is whether or not the plaintiff is entitled to interest at 14.25% per annum from that date to the date of judgment. In deciding this, consideration must be given to the law that governs the payment of interest on a demand promissory note after demand is made. The plaintiff’s position is that notwithstanding that the promissory note sued upon only calls for “interest payable monthly at the rate of 14.25% per annum until paid”, the parties may agree to an arrangement that would oblige the maker of the note (in this case the defendant company) to pay interest at such agreed rate notwithstanding that a demand for payment had been made. The usual rule is that where interest is payable at a certain rate “until paid”, interest is only payable at that rate until the note becomes due. Thus once a demand for payment is made, as was done here on July 19, 1982, the note is then due and interest thereafter shall accrue at the legal rate, i.e. 5% per annum. See: Beaver Lumber Company Limited v. Hophauf, 1932 CanLII 192 (SK CA), [1932] 1 W.W.R. 357. I do not dispute that the parties would be able to agree that interest payable after demand is made shall be in accordance with the interest called for on the face of the promissory note. However, there is no evidence of any such agreement between the parties in this instance and so the plaintiff’s contention cannot succeed.