The Racing Australia website and associated domains and services will be out of action for up to 10 hours from 7pm next Monday.
The organisation will move all of its existing systems from an on-premise data centre to the Oracle Cloud Infrastructure following a three-month assessment and testing process.
The relocation of the data will also impact sites including the Australian Stud Book, Stable Assist, XML services and secure FTP data services.
Principal Racing Authority webpages that are hosted by Racing Australia will also be down during the transfer.
Racing Australia is encouraging participants wishing to transfer ownership, licensing, nominations, acceptances, gear changes and scratchings to do so prior to the 7pm deadline.
The sites are expected to be back up and running by 5am on July 8.