Contractual notices are a double-edged sword. A common requirement by virtue of the conditions of construction contracts, contractual notices are often overlooked, easily forgotten once works commence on site and yet hugely important in terms of proper financial management of a project and in respect of claims for additional time or money. They are frequently contentious. This article examines notice provisions that are most likely to be encountered in practice, by reference to a main construction contract (although notice provisions may be found in sub-contracts, supply contracts and professional consultancy agreements alike), and looks at the legal issues arising from conflicts involving the failure to give proper contractual notices.