The Bureau of Internal Revenue (BIR) has recently issued Revenue Memorandum Circular (RMC) No. 91-2021 regarding the filing of returns and payment of corresponding taxes due thereon, and submission of reports and attachments falling within the period from August 6, 2021 to August 20, 2021 for taxpayers under ECQ and MECQ. Deadlines falling within the same period are extended for fifteen (15) calendar days; If the ECQ/MECQ will be extended, the filing and payment of returns, and submission of attachments shall also be extended for fifteen (15) days from the lifting of the ECQ/MECQ.
Source: https://www.bir.gov.ph/images/bir_files/internal_communications_2/RMCs/2021%20RMCs/RMC%20No.%2091-2021.pdf