The bureau recently published the Revenue Memorandum Circular (RMC) No. 105-2017 with regards to Revised Withholding Tax on Compensation Pursuant to the Amendments to the National Internal Revenue Revenue Code (NIRC) of 1997 as Introduced by Republic Act No. 10963, Other Known as the "Tax Reform for Acceleration and Inclusion (TRAIN) Law".
Republic Act No. 10963, otherwise known as the "Tax Reform for Acceleration and Inclusion (TRAIN) Law" is effective on January 1, 2018 to December 31, 2022. In this regard, beginning January 1, 2018, every employer making compensation payments in their respective employees shall deduct and withhold from such compensation a tax determined in accordance with the Revised Withholding Tax Table attached in ANNEX "A".
Please refer: https://www.bir.gov.ph/images/bir_files/internal_communications_2/RMCs/RMC%20No%20105-2017.pdf of the full text of RMC No. 105-2017.