Ok, British hair testing is slightly different than here in the U.S. I am not sure about this at all, but I think they are allowed to go back up to 2 years in the U.K. Your head hair grows about 1/ 2 inch a month so in the U.K. that would be 12 inches of hair. They can test back that far here in the states but it becomes inaccurate after about 90 days (1 & 1/2 inches) so the standard is set to use up to 1 & 1/2 inches off the scalp. Also, I think the amount of metabolites allowed in the hair may be different. Any chance you know the name of the lab or who the big drug testing labs are over there?