Consistency has real value for a signature scent, and most of the advice on this topic, reasonably, pushes toward picking one and sticking with it. That does not mean a signature scent should be permanently frozen in place. There are specific moments where a deliberate change makes more sense than blind consistency.
A rebrand or significant repositioning is a legitimate trigger. If your shop is genuinely repositioning toward a different tier of client, or refreshing its visual identity, updating the signature scent alongside that broader change keeps the sensory identity aligned with everything else that changed, rather than leaving an old signal attached to a new brand.
Client feedback, tracked deliberately rather than reacted to emotionally, is another legitimate trigger. If a specific scent is consistently drawing negative reactions from a meaningful share of clients, not just one or two isolated preferences, that is a real signal worth acting on rather than defending a choice out of stubbornness.
What is not a good reason to rotate: boredom on your end. You are exposed to the scent constantly, all day, every day, which means you will personally tire of it long before your clients do, since they only encounter it once every few weeks at most. Rotating based on your own fatigue with a scent, rather than genuine client signal or a real brand shift, risks undermining the consistency that made it valuable in the first place.
If you do decide to change, treat it deliberately: announce it, frame it as an upgrade or refresh, and make sure the change happens uniformly across every location and every team member at once.