FAS can be submitted at any point in time via the website (it is not dependent on when the annual return is due). In future, FAS will also be done via XBRL (but this is not possible as yet)
Disclaimer:
Please note that the information provided does not constitute legal or professional advice, but rather the applicability of existing theory to a given practical situation. Due care is taken to ensure that the information is correct, but it remains subjective and an interpretation of application of information.