The Bureau of Internal Revenue issued Revenue Memorandum Circular (RMC) No. 46-2022 in relation to RMC Nos. 42-2022 and 44-2022, particularly on the deadline of the submission of attachments to the 2021 Annual Income Tax Return (AITR).
The Circular clarifies that the deadline for submission is on or before May 31, 2022, whether electronically filed AITR is an original or an amended return.
The submission shall be made manually to the Revenue District Office (RDO) or to the Large Taxpayers Division where the taxpayer is registered, or electronically through the Electronic Audited Financial Statements (eAFS) System of the BIR.
Full text here: https://www.bir.gov.ph/images/bir_files/internal_communications_2/RMCs/2022%20RMCs/RMC%20No.%2046-2022.pdf