Negotiations should begin in November after Joshua and his team have been formally notified, but there is nothing stopping the two sides coming together before then.
Joshua's promoter, Eddie Hearn, has expressed that he wants the two squaring up for Joshua's next outing in November, however they'll need to go through the process of striking a deal quickly and the IBF has strict rules on making a mandatory defence early.
The IBF also clarified that January 9 is the date Joshua should fight Parker on or before.
According to their rules, a deal must be made within 30 days of the champion being notified, which would be December 9 at the latest, otherwise the fight goes to purse bids.
Under IBF rules, the heavyweight champion has to make a mandatory defence within nine months of winning a title, hence the January 9 date as Joshua defeated Charles Martin on April 9.