Hull breached Premier League ticketing rules last season by not offering concessionary prices to children and senior citizens in certain parts of the KCOM Stadium.
Following complaints from fans, the Premier League charged the club and an independent commission, compromised of two senior barristers and a former club secretary, was set up to consider the case.
The commission's verdict, announced on Friday, is that Hull were in breach of rule R.8 and must comply with it if they are promoted to the Premier League in the next five years.
In a statement, the Premier League said: "Following the commission's decision, Hull City has agreed, should the club be promoted to the Premier League in the future, that it will comply with Premier League rules regarding concessions.