PrestoExperts' clients can set deadlines for the delivery of their requested service. Deadlines are always open to negotiation, UNTIL the the Expert is hired. Once hired, the deadline cannot be changed unless both parties agree on a new deadline. Late delivery of a requested service can result in either the partial or complete loss of the Expert's session fee. If an Expert isn't certain that he can meet a client’s deadline, he should not accept the job, and alternatively the client should not hire him.