Changing to Non IMM O from OA

[DrJack54]

1 hour ago, farangkrab said:

When do I apply for the 1 year extension? With less than 30 days remaining (of the 90) or before the 30 days?

Most immigration offices do the extension from 30 days prior up till expiry of the 90 stamp.

Some offices allow up to 45 days early eg CW, CM etc.

 

Obviously do it early enough to attend to any added requests from immigration