The Malaysian businessman has written off around £5.8 million owed to him, while there has also been a reshuffle at the club with a new structure implemented to oversee transfers
Tan took control of the Premier League side in 2010 when he bought a 36.1 per cent stake in the club and had backed manager Malky Mackay financially to enable their promotion push last season.
Under an agreement between the club and Mr Tan, he was owed the interest relating to his loans, however, he has opted to forgo that and allow the club to retain the money.
Tan has also confirmed that any future loans he makes to the club under £50m will be interest free.
"Vincent Tan has agreed to write off interest of approximately £5.8 million on previous loans made to the club," a statement on Cardiff's official website read.
"And (Mr Tan) stated that all future loans up to an aggregate value of £50 million will also be interest free."
The announcement was made following a board meeting at the Cardiff City Stadium, and it was also revealed that Len Win Kong has resigned as a club director.
The meeting – which Mackay was present at – also confirmed plans to look into expansion of the club's stadium and that a Nomination and Corporate Governance Committee will support Mackay in relation to all transfers and made it clear the Scot will have final approval on any deals.