Yes usually immediate. Sometimes an IT glitch can occur (shocking with Hyatt - LOL!). But a call usually resolves that quickly. You could also call in if you're switching from 1 Hyatt to the other and explain you need the points from the 1 to book the other but want to make sure the new one is available before cancelling old - they can handle both for you on the same call so that you don't run any "risk".