The Toni and Guy website is a little daunting to navigate but once you know what you need to do, it is relatively straight forward. However, if in doubt use the Search widget.
First locate the salon you want or pick one at random using the Salon Finder. I chose a London and a Hampshire based salons to do a comparison. The details are the same. Go to the Prices drop down and scroll down to the Booking information.
‘All clients must have a skin allergy test 48 hours prior to a technical appointment unless a technical service has been carried out in the last three months.’