Although not mandatory, given that the FCA are likely to consider whether firms have complied with the guidance when considering supervisory or enforcement action (and the FOS are likely to pay similar regard to the guidance) all firms should consider the guidance and their policy on dealing with vulnerable customers and document that they have done so, and the action taken. 

This should include some training to all staff on dealing with and recognising vulnerable customers. The level and type of training needed will of course vary from firm to firm - depending on what part of the sector they operate in, the risks arising in relation to vulnerable customers will change. Firms that engage in consumer lending for example, may need to take different steps to firms that are involved in the provision of investment products or services. The guidance will however be relevant to all firms and the first line of defence against regulatory action and the first step for placing customers at the heart of your business is to show that you have acted on the guidance.