The Queen will not have a Melbourne Cup runner following the decision Estimate will end her career in Europe.
The Sir Michael Stoute-trained five-year-old won her first race since her 2013 Ascot Gold Cup success when she took out the Doncaster Cup last week.
That victory sparked talk of a possible trip to Australia but it seems a trip to France or a return to Ascot on British Champions Day are more likely targets.
"Estimate is not going to Melbourne and we will be looking at the Qipco British Champions Long Distance Cup and possibly the Prix du Cadran before that. Ascot is the preferred option at this point," John Warren, the Queen's racing and bloodstock advisor, said.
Estimate was beaten just a quarter of a length by Leading Light in defence of her Gold Cup earlier this season, but flopped when last of eight on a fast surface in the Goodwood Cup, ground she would have been likely to get at Flemington in November.
"The decision came down to a number of factors," Warren told the Racing Post.
"On analysis we felt it was probably in the best interests of the filly herself not to have her go all the way to Australia. She has done the Queen very proud."
The Dermot Weld-trained Pale Mimosa, who beat Estimate in the Lonsdale Cup at York last month, is also unlikely to go to Melbourne.