Codes and guidance, even if made under legislation, are not legislation; the question then arises as to their status. To what extent must addressees of any such code or guidance comply with them, and is there a difference in status between codes and guidance?
Quasi-legislation is either statutory or non-statutory. While statutory and non-statutory quasi-legislation may have a similar effect, the fact that the code/guidance is a statutory requirement means the issuing of it in the first place would lie beyond challenge. So, the fact that Ofcom introduces guidance about women and girls cannot be challenged.
The House of Lords considered a statutory code of practice in R (Munjaz) v Mersey Care NHS Trust  UKHL 58. The case was brought by a mental patient who complained about imposed periods of seclusion because the hospital had not followed the appropriate Code of Practice.
“It is in my view plain that the Code does not have the binding effect which a statutory provision or a statutory instrument would have. It is what it purports to be, guidance and not instruction. But … the guidance should be given great weight. It is not instruction, but it is much more than mere advice which an addressee is free to follow or not as it chooses. It is guidance which any hospital should consider with great care, and from which it should depart only if it has cogent reasons for doing so” (at para. 21). [our italics]
This quote indicates that there is no formal distinction between a code and a guidance document – here the court uses these terms interchangeably. While there may be no formal distinction taken across legislation as a whole, where both codes and guidance are required by the same legislation presumably a distinction would have to be made. The second point is that even if these forms of quasi-legislation are not formally binding, they are not ignorable either; there must be good grounds for not following them. Note, however, that different Law Lords gave slightly different emphasis as to what constituted good grounds for disregarding the code. Moreover, there is a presumption in construing Acts of Parliament that each provision is intended to have a legislative purpose and clearly a provision permitting or requiring the production of a code of conduct or practice is of no value if there are no legal consequences (however subtle) of the code.
Given there is no specific status automatically attached to either a code or guidance, the precise level of deference from addressees to their contents will depend on the terms in which they are provided for in the legislation.
Codes of Practice
Looking first at codes, it is normal for the parent statute to provide that breach of a code of practice or conduct does not of itself impose criminal or civil liability (see e.g. s 14(3) Animal Welfare Act 2006), but that the courts can consider breaches in determining any question of liability to which the code appears relevant (see e.g. s 12(4)(b) Human Rights Act) – as in the OSA.
Looking at the reasoning in Munjaz, and the fact that codes are not the same as legislation, it would seem that the codes are not generally prescriptive except if and insofar as both the parent Act and the code itself so provide, whether expressly or by clear implication. Since the OSB explains that the codes to support compliance with safety duties apply on a ‘comply or explain’ basis, this would not seem to be the case here. Nonetheless, the fact that compliance with those codes would satisfy the corresponding duties would suggest that they are more than advisory and may indicate a minimum standard/benchmark. The reasons for departing from the code would have to be particularly strong; failure to comply could expose a service to a breach of duty (Cls 49 and 50 HL Bill 164 (as amended on Report)). The position here seems to be similar to approved codes of practice (ACOPs) issued by the Health and Safety Executive under section 17 of the Health and Safety at Work Act 1974. For HSE explanation of status of ACOPs see here: https://www.hse.gov.uk/legislation/legal-status.htm
The Status of Guidance
Turning now to guidance, this approach can be used in a range of contexts, but it is usually envisaged as being to advise or inform, in accordance with the normal English usage. In R (English UK Ltd) v SoS for the Home Department  EWHC 1726 (para 106) the Court described guidance as supplementing and influencing the application of black letter law. Usually, they are drafted in non-prescriptive terms (but cf NICE guidelines which are increasingly drafted in clear, unambiguous and prescriptive terms on the basis of current evidence). The classic statutory requirement in relation to guidance is to “have regard to” it. In the context of government guidance to local authorities, the courts have held: “Parliament by section 7(1) has required local authorities to follow the path charted by the Secretary of State’s guidance, with liberty to deviate from it where the local authority judges on admissible grounds that there is good reason to do so, but without freedom to take a substantially different course” (R v Islington LBC ex p Rixon  1 CCLR 119 at 123).
This means that addressees are not required to blindly follow the guidance, but neither can they read the guidance and then ignore it. According to R (Daniel Thwaites plc) v Wirral Borough Magistrates  EWHC 838 (Admin), the person deciding is required to pursue its own thought process to reach a result seeming appropriate in all the circumstances but, it should:
- Remember the approach the guidance suggests; and
- Not depart from the guidance on the basis of a general disagreement but only on the basis of considerations relevant to the case in hand which requires a different approach. See also R (Elizabeth Rose) v Thanet Clinical Commissioning Group  EWHC 1182 in which the defendant’s policy was inconsistent with the guidance; the defendant was not free to not follow guidance just because they disagreed – other cases have suggested that there has to be a ‘special factor’ which ‘exceptionally justified departure’: R v North Derbyshire Health Authority, ex parte Fisher  7 WLUK 276. This case could be read as suggesting that the default position is that the guidance should be followed and justification is required for a move away from this default position.
In a discussion about the difference between statutory and non-statutory guidance, the Administrative Court (in the context of guidance on the use of tactile paving to assist the visually impaired) held in Ali v London Borough of Newham  EWHC 2970:
[…] the weight that should be given to particular guidance depends upon the specific context in which the guidance has been produced. In particular (without intending to create an exhaustive list) […] it is necessary to give due regard to the authorship of the guidance, the quality and intensity of the work done in the production of the guidance, the extent to which the (possibly competing) interests of those who are likely to be affected by the guidance have been recognised and weighed, the importance of any more general public policy that the guidance has sought to promote, and the express terms of the guidance itself” (at para. 39).
As a result of their advisory status there are generally no specific enforcement processes around the guidance itself – enforcement would come in relation to the primary duty to which the guidance is relevant.
In sum, neither codes nor guidance are formally binding. Both however must be taken into account – and this means engaging with the content of these documents and being open to challenge on decisions made as a result of engaging with it (eg either to follow it, diverge from it, or ignore it). While there is potential overlap between codes and guidance, and despite the language in Munjaz, it seems that the obligations in the codes may be more hard-edged than for the guidance and may carry more weight in terms of compliance. This point might be particularly the case for the OSA because it contains both Codes and Guidance; the distinction must be understood to have some difference even if it is only slight.