Maximum age rules under which former champions are given automatic entry will be changed.
The Royal & Ancient Golf Club said Tuesday that former champions will only get automatic entry if they are under 60 - a reduction of five years from the current 65. But the age limit will be phased in over time.
"Therefore, the existing past champions' exemption has been changed to allow those currently aged between 60 and 65 to be eligible until the age of 65, whilst those under 60 will be eligible until they reach 60 years of age," the R&A statement said.
This means that former champions born between July 20, 1942, and July 19, 1948, will be allowed to enter until they are 65. But other former winners younger than that will only be able to enter until they are 60.
In other changes, the runners-up in the British Amateur, U.S. Amateur and European Amateur Championships will be exempt from regional qualifying. So will the 10 highest-ranked entrants on the R&A's world amateur golf ranking in the week beginning May 26.
The 2008 British Open is at Royal Birkdale, northern England, from July 17-20.