28 September 2026
At Therapy, a patch test is required at least 48 hours before any lash lift, lash tint, brow tint or hair colouring service. It is quick, it is free of charge, and it cannot be done on the same day as the treatment itself. If you have not had one, the appointment cannot go ahead, so it is worth sorting out as soon as you book rather than in the week of your visit.
Contents
- Which treatments need a patch test?
- Why does the test have to be 48 hours in advance?
- Can I have a patch test on the day of my appointment?
- How much does a patch test cost?
- What happens if I have not had one?
- How do I fit the patch test around my booking?
- Which treatments do not have a published patch test requirement?
- Frequently asked questions
- Book your appointment in Canterbury
- Further reading
Which treatments need a patch test?
Four groups of treatment at Therapy require one. A lash lift at £45 and a lash tint at £25 both need a patch test at least 48 hours beforehand, whether you book them separately or together. A brow tint at £15 needs one on the same terms.
All hair colouring services need a patch test at least 48 hours before the appointment. That covers every colour service on the price list: highlights at £130 for a T section, £145 for a half head and £170 for a full head, global colour at £105 for a regrowth and £120 root to end, and balayage at £170 partial and £195 full custom.
The requirement attaches to the product rather than to how much of it is used. A T section of highlights needs a patch test exactly as a full head does, and a lash tint needs one exactly as a lash lift and tint together would.
Why does the test have to be 48 hours in advance?
A patch test places a small amount of the product on your skin so that any reaction has time to show before the product goes near your eyes or scalp. Reactions are not always immediate, which is the whole reason for the waiting period. Testing an hour beforehand would not give a delayed reaction time to appear, so it would not tell anyone anything useful.
Forty eight hours is a minimum rather than a target. Having the test a week or a fortnight ahead is fine, and usually easier to arrange around a trip into town you were making anyway.
Can I have a patch test on the day of my appointment?
No. A patch test cannot be carried out on the same day as the treatment, however far in advance the treatment itself was booked. Booking a colour appointment three months out does not change the rule, because the 48 hours is counted from the test, not from the booking.
This is the single most common reason a first appointment has to be moved, and it is entirely avoidable. If you are booking online or by telephone, ask about the patch test in the same conversation rather than leaving it until a reminder arrives.
How much does a patch test cost?
Nothing. Patch tests at Therapy are quick and free of charge. The only thing they cost you is the timing, which is why planning them early matters more than anything else about them.
Because there is no charge, there is no reason to put one off while you decide between, say, a half head and a full head of highlights. The test covers the colour service rather than the particular size of it.
What happens if I have not had one?
The treatment cannot go ahead. That applies to a lash lift, a lash tint, a brow tint and every hair colouring service, and it applies whether the omission was a misunderstanding or a diary problem.
It also runs into the cancellation terms. Cancellations or amendments require 24 hours notice, and appointments cancelled with less than 24 hours notice incur a 50 percent charge. Finding out on the day that a patch test is missing is a poor way to discover that policy, so treat the test as part of the booking rather than as an afterthought.
How do I fit the patch test around my booking?
Deal with it at the point of booking. When you reserve a colour, lash or brow appointment, agree a time to come in for the test in the same conversation, and put both in your diary together.
If you are working towards a fixed date such as a wedding, a holiday or a party, count backwards. The treatment needs to sit far enough ahead of the event for the result to be right, and the patch test needs to sit at least 48 hours ahead of the treatment. Our guide to booking wedding hair and beauty sets out how the rest of that run-up fits together.
If you are combining treatments, one visit can often cover the testing for more than one of them. Say what you are planning to book when you come in, rather than only what is in the diary at that moment.
Which treatments do not have a published patch test requirement?
Therapy states a patch test requirement for lash lifts, lash tints, brow tints and hair colouring. No such requirement is published for waxing, spray tanning, nail treatments, cutting or blow drying.
That is a statement about what the salon publishes rather than a promise about your own circumstances. If you have had a reaction to a product before, or you are unsure about something you are booking, say so when you book and it can be checked properly.
Frequently asked questions
How long before my appointment do I need a patch test?
At least 48 hours. Earlier than that is fine, and often easier to arrange, but the test cannot fall inside the 48 hours before the treatment.
Is there a charge for a patch test at Therapy?
No. Patch tests are quick and free of charge.
Can I have the patch test and the treatment on the same day?
No. A patch test cannot be done on the same day as the treatment, however far in advance the appointment was made.
Does a T section of highlights need a patch test?
Yes. All hair colouring services require a patch test at least 48 hours prior to the appointment, regardless of how much colour is applied.
Do I need a patch test for a brow tint as well as a lash tint?
Yes. Brow tint, lash tint and lash lift all require a patch test at least 48 hours beforehand.
What happens if I turn up without a patch test?
The treatment cannot go ahead. Cancellations or amendments require 24 hours notice, and appointments cancelled with less than 24 hours notice incur a 50 percent charge.
Book your appointment in Canterbury
Therapy is at 21 Burgate in Canterbury, a short walk from the cathedral. If you are planning a colour service, take a look at our hair services, and for lash and brow treatments see our body and beauty services. Mention the patch test when you get in touch through our contact page and we will book it in alongside the appointment itself.
