Treatment guide
Hair colour: patch tests, damage and what to ask
Hair colour is not licensed anywhere in the UK, but it is the hair service most likely to injure someone. Permanent dyes contain PPD, a recognised allergen, and a reaction can be severe. A patch test at least 48 hours before the appointment is the single most important thing a salon does.
Last reviewed · How we research and check this
Is it regulated?
No licence is required to perform this anywhere in the UK. Cutting, colouring and styling do not penetrate the skin or apply light, electricity, cold or heat, so they fall outside the scheme’s definition altogether rather than merely awaiting it. Qualification and insurance still matter, and no law requires either.
Basis: Section 180, Health and Care Act 2022 and the Government's consultation response of 7 August 2025, tracked in House of Commons Library briefing CBP-10331.
What the practitioner should hold
Level 2 covers basic colour; Level 3 covers correction, balayage and high-lift work. Colour correction on damaged or previously boxed hair is genuinely difficult and worth asking about specifically.
Insurance
Treatment-risk cover should name colour services. Insurers commonly make cover conditional on patch testing every client, which is why a salon that skips it may be uninsured for the very thing most likely to go wrong.
What it costs
Guide price: we do not yet have enough member listings to publish a reliable range for colour. We publish this figure only when there is real data behind it.
Questions to ask before you book
- Will you patch test me, and how long before?
- What is your policy if I have reacted to hair dye before?
- Have you corrected colour on hair like mine?
- What condition will my hair be in afterwards, honestly?
Red flags
- Offering to colour today with no patch test
- Dismissing a previous reaction as unimportant
- No strand test before a big change
- Guaranteeing a result from a photo without seeing your hair
Common questions
How long before colouring should a patch test be done?
At least 48 hours before the appointment, and repeated if it has been a while or the product has changed. Manufacturers specify the interval and insurers generally require it.
Is hair dye regulated in the UK?
The products are — cosmetic ingredient rules restrict what can be sold and at what concentration. The act of applying it is not licensed, and no qualification is legally required to colour someone's hair professionally.
Members offering colour
No members offer this yet. List your business if you do.