The NRL will introduce a limit on football club spending next year in the biggest club equalisation measure since the establishment of a salary cap.

The governing body and its clubs are in the process of signing off on a whole-of-game funding agreement that effectively extinguishes any threat of a Super League-style breakaway competition. Rugby League Central has sent all clubs a copy of the memorandum of understanding which, when signed, will become a binding agreement that secures their financial future and holds them to a perpetual license to play in the NRL competition.

It's understood the document - obtained by Fairfax Media - has been signed off by a number of clubs. Others are expected to do likewise to qualify for the promised up-front payment of $1.125 million each in early July, made possible by the record broadcast deal. The clubs stand to earn an additional $100 million from 2018 to 2022, with additional grants totalling 130 per cent of player payments over that period.