Under previous rules, testers would try three times in five days to reach the athlete to reschedule if he or she missed a scheduled drug test.
Now UK Sport requires athletes to be available at a specific time and place five days a week to be tested between contests -- the prime time to combat illegal drug usage, UK Sport told the London Telegraph.
Athletes who miss three tests in an 18-month period will be classified as having tested positive for drugs.
"Never before have we had such a powerful set of rules," said John Scott, director of the UK Sport program.
Sports that get funding from UK Sport or sports councils in England, Scotland, Wales and Northern Ireland must follow the new policy, the newspaper reported.