Is overtime included in 13th month pay?

Overtime pay isn’t included in 13th month pay, since the computation covers basic salary only. Basic salary includes:

• Regular pay for work done
• Wage increases required by law

It excludes:

• Overtime pay
• Night shift differential (extra night pay)
• Holiday premium (extra holiday pay)
• Cost-of-living allowance (COLA), unless included in basic pay
• Cash payout for unused leave credits

A company policy or a collective bargaining agreement (CBA) — a deal between a company and its union — may include these anyway, though the law doesn’t require it.