SEC Memorandum Circular No. 3 Series of 2021
All stock corporations with fiscal year ending December 31, including branch offices, representative offices, regional headquarters and regional operating headquarters of foreign corporations, shall enroll and file their AFS through OST depending on the last numerical digit of their SEC registration or license number in accordance with the following schedule:
June 1-30
July 1-31
August 1-31
September 1-30
October 1-31
November 1-30
1
2
3 & 4
5 & 6
7 & 8
9 & 0
All stock corporations may enroll and submit their reports through OST even prior to their respective coding schedule.
Source: https://www.sec.gov.ph/wp-content/uploads/2021/03/2021MCNo03_.pdf