Magic Millions is certain its National sale will go ahead - albeit a week later than scheduled.

The sale with a catalogue of more than 800 horses, was due to start on Monday at the Gold Coast sales centre.

Magic Millions has announced the sales will be put back a week to start on Monday, week July 27.

A COVID-19 cluster has been linked to the Crossroads Hotel in southwest Sydney, near where the second round of the Inglis Easter Yearling Sale was held recently.

Managing director Barry Bowditch said Queensland authorities had declared some the areas in southwest Sydney as hotspots which led to travel restrictions.

"Given the restrictions are now in place, we've decided to postpone the sale which will give all participants the best opportunities to attend," Bowditch said.