Hannon will choose between the Queen Elizabeth II Stakes and the Qipco Champion Stakes on October 21 for his St James's Palace Stakes winner, who has been placed behind Ulysses in the Coral-Eclipse and Juddmonte International on his last two starts.
"He will now go to Champions Day for either the mile (QEII) or the Champion Stakes," said Hannon.
"He was entered early on in the year in Ireland, but he is not going there as he had a hard enough race in the International."
The Marlborough handler has a choice of engagements for Tajaanus after she registered her third win from four starts in the Group Three Sweet Solera Stakes at Newmarket.
"She is in the Rockfel and the Fillies' Mile and will likely go for one of those next. She looks great at home and is as big as ever," said Hannon.