There is no legal requirement in the UK forcing brands to print an exact concentration on every bottle, so some choose not to, either because the formula genuinely does not fit neatly into a standard category, or simply because the marketing team decided not to include it.

A Few Honest Possibilities

Sometimes a fragrance is deliberately formulated between two standard tiers and the brand would rather avoid confusion than pick a label that only partly fits. Other times it may simply be an oversight, a stylistic choice to keep packaging minimal, or a deliberate move by a brand that would rather you judge the product by wearing it than by comparing a percentage on the box.

What to Do If It Is Not Stated

Look at how the product is named, since eau de parfum, eau de toilette and similar terms usually give you a reasonable clue even without an exact percentage, and if longevity really matters to you, ask the retailer directly before buying. Our guide to perfume concentrations explains naming conventions properly, and our complete guide to perfume has more general buying guidance.