X advances to Y Rs.10,000 on the guarantee of Z. The loan carries interest at ten percent per annum. Subsequently, Y becomes financially embarrassed. On Y’s request, X reduces the interest to six per cent per annum and does not sue Y for one year after the loan becomes due. Y becomes insolvent. Can X sue Z?
X cannot sue Z, because a surety is discharged from liability when, without his consent, the creditor makes any change in the terms of his contract with the principal debtor, no matter whether the variation is beneficial to the surety or does not materially affect the position of the surety.