Westland Savings Bank v Hancock - [1987] 2 NZLR 21

Contract — Rectification — Mortgage — Loan offer from bank specified interest at current rate — Mortgage subsequently executed restricted the power of the bank to increase the interest rate — Bank and the mortgagors were both unaware of the restriction in the mortgage — Whether the mortgage should be rectified to delete the restriction.

Equity — Estoppel — Conduct — Bank, as mortgagee, and the mortgagors were both unaware of a term of a mortgage preventing the bank from increasing the rate of interest at intervals of less than three years — Bank had increased the rate at shorter intervals from time to time over 11 years, and the mortgagors had accepted the increases without demur — Whether the mortgagors were estopped from alleging that previous interest rate increases were invalid under the mortgage.