These are payments made by an employer to a contractor which are not authorized by the contract. They are occasionally paid when a contractor has performed very much to the satisfaction of the employer but has shouldered some extra cost clearly not attributable to his own actions, such as exceptionally bad weather or some other misfortune outside his control. Only the employer can decide to make an ex-contractual payment, not the engineer or other person acting on his behalf; and the employer must himself have power to make the payment. Hence a private person or company may be able to make an ex-contractual payment; but a public authority will usually have no such power.