Desk research against primary sources, with the issuing authority linked where a page states an official fee, rule or deadline.
The sequence matters more than the paperwork itself: secure a written offer from the new school first, and only then request withdrawal and the transfer certificate from the old one. Doing it the other way round leaves a window where your child is enrolled nowhere, which matters for KHDA registration continuity as well as for your own peace of mind.
A waiting list for a specific year group can move quickly once a place actually opens, so treat any informal indication of interest from a school as provisional rather than a place you can plan around. If two children in the family are moving together, check both year groups separately — one filling before the other is common and can force an awkward decision about staggering the move.