Featherstone missed out on this season before it started, having been denied RFL membership due to their ongoing financial issues.
Halifax went into liquidation before the club subsequently regained their RFL membership and their place in the Championship earlier this season.
Meanwhile, North Wales Crusaders had been on the verge of going bust, with players going unpaid and two games being cancelled prior to a group of supporters and volunteers rallying to form a new company which was subsequently granted an interim licence by the RFL.
“It is surely beyond dispute that spending by some poorly run clubs has been unsustainable for a number of years and in many cases the inevitable then happens,” said RFL chair Nigel Wood OBE.
“We want the rule book to protect and support the well-run clubs as far as possible.
“Linking spend to income does not hamper progressive clubs looking to build but it should act as something of a handbrake on spending that is unsustainable.
“It also encourages clubs to maximise their revenue streams as, the more they generate, the more they are allowed to utilise on their squad and I am delighted the Championship clubs have unanimously supported our proposals.”
The league said it would now work with each club individually to confirm their salary cap based on turnover before the end of June, in addition to taking on board the past two years’ accounting periods.
Clubs will also be able to apply for an increased cap spend and “transitionary arrangements will apply to clubs who already have existing contractual commitments”.
Any such application, however, will be subject to a five-stage test which takes into account unpaid His Majesty’ Revenue & Customs (HMRC) payments, pension payment arrears or being placed into special measurements, with “higher surety being required, plus RFL board approval”.
In addition, clubs were informed of a proposal to reduce the number of “non-federation-trained” players – in essence, overseas players – down from an unlimited number to seven, with the number again reduced to five in 2028.