The computation, step by step
13th month pay = total basic salary earned in the year ÷ 12. Three things trip people up: the base is basic salary only (no OT, premiums, or allowances); it prorates by what was actually earned, so mid-year hires and resignees get a proportional amount; and leave without pay reduces the base. Deadline: December 24. Tax: exempt up to the ₱90,000 bonus threshold.