Negligence by a professional person can give rise to liability to the victim in contract or in tort. There is usually some contractual arrangement between the claimant and the professional person whereby the latter came to be appointed to provide the professional services in question. Any contract whereby a person was appointed to provide professional services would, in the absence of any exclusion clause, contain express or implied obligations to provide the services with reasonable skill and care to be expected of such a professional in such circumstances. The content of such implied term would almost always be coterminous with the duty of care which such relationship would give rise to as between the parties to the contract. In such circumstances the only differences between pleading the case in tort and pleading it in contract would be:
There are of course situations where a professional person will come under a duty of care to a claimant despite the absence of a contractual arrangement between them. In such case, only a claim in tort will be available.
It is a question of law and fact as to whether or not a duty of care arises. Although ultimately the exercise is a balancing one, the existence of a notional duty will arise, as a matter of law, if three criteria are satisfied (Caparo Industries Plc v Dickman  2 A.C. 605, HL and Spring v Guardian Assurance Plc  2 A.C. 296, HL):
In Caparo Industries Plc v Dickman  2 A.C, 605 at 618 Lord Bridge stated that, whilst he recognised the importance of the underlying general principles, the law had moved in the direction of attaching greater significance to the more traditional categorisation of distinct recognisable situations as guides to the existence, the scope and the limits of the varied duties of care which the law imposes. This is often referred to as the “incremental” or pragmatic approach, whereby in deciding whether or not there is duty of care in a new situation the courts should decide gradually, step by step and by analogy with previous cases and, as a result, in some situations, only limited reference will be required to be made to the “threefold” test.
The elements of foreseeability of damage and proximity and considerations of fairness, justice and reasonableness are relevant to all cases whatever the nature of the loss (Marc Rich & Co. v Bishop Rock Marine Co. Ltd  1 A.C. 211, HL). However, in relation to economic loss, assumption of responsibility (which was first enunciated in Hedley Byrne & Co. Ltd v Heller & Partners Ltd  A.C. 465, HL) has been identified as the key criterion. Once that principle has been shown to be satisfied there is no need to embark on any further inquiry whether it is fair, just and reasonable to impose liability for economic loss (Henderson v Merrett Syndicates Ltd  2 A.C. 145, HL, White v Jones  2 A.C. 207 HL and Williams v Natural Life Health Foods Ltd  1 W.L.R. 830, HL). However, it has been suggested that whichever approach is adopted the same result should be yielded and, therefore, it should not matter whether the “three-fold” test, the “incremental” approach or the assumption of responsibility test is applied (Bank of Credit and Commerce International (Overseas) Ltd v Price Waterhouse (No. 2)  P.N.L.R. 564, CA and Parkinson v St James and Seacroft University Hospital NHS Trust  EWCA Civ 530;  3 Q.B. 266 at 274A, CA).
More recent case law has recognised that it is impossible to reconcile all the judicial statements on the correct methodology to be applied to novel situations in which a person is alleged to owe a duty of care to another, and that the courts should take a more cautious approach to imposing that duty where economic loss is claimed than in relation to physical damage. The appropriate course for ascertaining whether there is a duty of care in an economic loss case is to look at any new set of facts by using each of the three approaches namely, the threefold test, the voluntary assumption of responsibility test and the incremental test which disclosed no single common denominator by which liability could be established: see, for example, Commissioners for Customs and Excise v Barclays Bank Plc  UKHL 28;  1 A.C. 181, HL. When determining whether a duty of care is owed the court will focus its attention on the detailed circumstances of the case and the particular relationship between the parties in the context of their legal and factual situation taken as a whole.
The same standard of care is required of all professional men and women. It is that of “an ordinary skilled man exercising and professing to have that special skill. A man need not profess the highest expert skill, it is well established law that it is sufficient if he exercises the ordinary skill of a competent man exercising that particular art”: and Bolam v Friern Hospital Management Committee  1 W.L.R. 582. The standard expected is not dependent on the training and experience of the individual involved but is that of a person holding a particular rank or professing a particular specialist or, in a medical context, a specific post in a particular unit: see Wilsher v Essex Area Health Authority  Q.B. 730 (reversed by the House of Lords on a different point). A hospital or firm may be liable for a failure to provide a practitioner of sufficient skill, for example, a junior doctor when a consultant is required.
A doctor is not negligent if he or she acts “in accordance with a practice accepted as proper by a responsible body of medical men skill in that particular art. … Putting it the other way round, a man is not negligent, if he is acting in accordance with such a practice, merely because there is a body of opinion who would take a contrary view”: Bolam, above. In other words, it is not appropriate for the court to determine which of two bodies of distinguished medical opinion it prefers (Whitehouse v Jordan  1 W.L.R. 246). This applies to diagnosis (Maynard v West Midlands Regional Health Authority  1 W.L.R. 634) and advice (Sidaway v Bethlem Royal Hospital Governors  A.C. 871) as well as to treatment. The test also applies to causation where an issue as to standard of care arises. Where it is established what course would, but for the negligence, have been adopted and that the outcome would have been the same, the claimant has to prove that no responsible body of medical opinion would support such a course (Bolitho v City & Hackney Health Authority  A.C. 232). The same principles apply to all professions (Saif Ali v Sydney Mitchell  A.C. 198, per Lord Diplock at 220D).
As to what constitutes a body of medical opinion sufficient to satisfy the Bolam test, Lord Browne-Wilkinson said in Bolitho, above at 243C, that it is not enough that a number of medical experts are genuinely of the opinion, the opinion must be reasonable and responsible. However, “it will very seldom be right for a judge to reach the conclusion that views genuinely held by a competent medical expert are unreasonable”. He or she could only do so when satisfied that the opinion cannot be supported. In Smith v Southampton University Hospital NHS Trust  EWCA Civ 387; (2007) 96 B.M.L.R. 79 the Court of Appeal indicated that, where the experts are largely in agreement as to what has gone wrong and only differ as to whether it amounts to negligence, the court should decide between them and not simply rely on the Bolam test. See also Edward Wong Finance Co Ltd v Johnson Stokes & Master  A.C. 296 (a case on solicitors’ negligence where the adoption of a widely used practice was held to be negligent). In Sidaway, above, the majority of the House of Lords did not recognise that there might be circumstances where the risk involved in medical treatment was so grave that its disclosure would obviously be necessary to informed consent, notwithstanding any responsibly body of medical opinion or practice.
A duty similar to that in tort will normally be implied into a contract for professional services provided this does not conflict with express terms.