This chapter explains why therapists need to attend first and foremost to the ways in which an emotion is valid or ‘makes sense’, before moving in to offer a change procedure. The essence of validation might be working how out much crossness a client needs to keep in the event of an argument, rather than assuming that the anger is a problem. The author introduces the concept of obtaining an invitation to treat for each session, gaining the client’s willingness through validation procedures. Validation is also used to help the client who cannot identify their emotions, and to work out if there is ever a situation in which an emotion is simply not valid at all, the ‘zero option’. An example scenario is given in which a therapist validates inadequately, showing how quickly the session can deteriorate.