All 12 top-flight teams voted unanimously to amend the stipulation over concerns that it could plunge the rugby union transfer market into chaos, reports BBC Sport.
Before the amendment was made, a player could be bought out of his contract for a set transfer fee, a one-off payment of a year's salary based on what the buying club is offering or what he is currently being paid, whichever amount is higher.
Under the new system, the fee will become a negotiation between the two clubs, which will fall outside of the salary cap.
The change was introduced to prevent teams from poaching players from smaller clubs which pay smaller salaries, as well as preserve competitiveness and equity in the Premiership.
The Rugby Players' Association was not consulted about the vote.