If you have Instant Play enabled on your account, you will almost never have to wait for your credits to be ready to play.
If Instant Play is not enabled, there may be a delay of a few minutes or more for your credits to be available to play. In rare cases it might take a few hours. This is caused by the fact we are waiting for the race or races you bet on to finish and the results confirmed and reported to us. Once you're good to go, we'll shoot you an email so you can start playing.