This means that the Primera Division, Bundesliga, Premier League and Serie A will all have four teams entered straight into the group stage of the competition.
As things stand, Germany, England and Spain all get three guaranteed places with the fourth side needing to go through the qualification round, while Italy only has two places in the group stage, with a third needing to qualify, so the rule changes will be a big boost.
The Europa League winners will now also enter the competition in the group stage rather than needing to go through a round of qualifying.
The European football body announced a revamp of the coefficient system by which clubs are ranked and will now take historical success into account.
The final major change is in the way the money paid to clubs is calculated.
"A new four-pillar financial distribution system (starting fee, performance in the competition, individual club coefficient and market pool) will see sporting performances better rewarded, while market pool share will decrease," UEFA general secretary ad interim Theodore Theodoridis explained.
"The evolution of UEFA's club competitions is the result of a wide-ranging consultative process involving all stakeholders and taking into account a wide range of expertise and perspectives.
"The amendments made will continue to ensure qualification based on sporting merit, and the right of all associations and their clubs to compete in Europe's elite club competitions.