3.01 The principle of contractual estoppel is of great practical utility and has been widely applied. Its applications are not limited to enforcement of standard banking disclaimers in financial sector disputes, but may be found in contexts that are as diverse as commercial life itself.1 This chapter examines those which the courts have had occasion to consider, and there is little doubt that further applications will be developed as commercial parties take greater advantage of this particular aspect of their contractual autonomy. Practical benefits of the principle appeal not only to commercial parties: contractual estoppel has been applied in context of domestic arrangements of varying degrees of complexity.2