A consultant is liable and has to indemnify the client for any loss, liability, costs, damages or expenses arising from a breach of duty or negligence.
You can choose to limit this liability to a specified maximum amount or to the total amount paid by the client. However, in practice, liability limits can be difficult to enforce, especially if the client is a consumer (ie a private individual). Therefore, this agreement requires the consultant to have adequate insurance in place. Read Limitation of liability clauses to find out more.