To supplement what is said above, which is very informative, notification occurs even at 99% of margin, which I didn't know:
Will I get notified?
There are two points at which we will aim to notify you that you are on margin call, before we start automatically closing positions.
When your equity drops beneath…
We will endeavour to…
99% of margin
Send you a notification email
75% of margin
Send you a second notification email*
50% of margin
Start automatically closing positions
*If your equity level moves below 75% multiple times on a single margin call, we won’t send you multiple notifications.