Incentives tax? please help

gud day Im a Salesman Who has A monthly Quota If i Hit the target quota makakakuha ako ng 1% na Incentives every 3rd month ng susunod n buwan.
for example my Quota is 500k a month i will get 5k per month .. pero ang nkukuha ko lng is 4k or less
panu po ba computation ng tax para sa incentives although nag inquire ako sa Accounting dept ng company they said na taxable daw kc ung items na binebenta namin that's why na meron tlgang tax na kinakaltas.. un lang gumugulo sa isip ko may nakikita ako with holding tax sa payslip ko na 300-400 minsan na akala ko nabawas na nila sa 5k na dapat na incentives ko kaya sila nagbigay ng 4k na incentives.. i mean 4k na lng nkukuha kong incentives less withholding tax pa.. pero d nakadeclare sa payslip na binawasan na nila ako ng 1k.. please help me nacoconfuse na din kc ako.. i have been working on the company 7 mos. til now and i hit my monthly quota ever since n mag start ako .. mejo mlaki na ung nawawala na tax daw...

yes, those incentives are taxable because they become part of income. whether the computation is correct, it will really be at the end of the year when the final income and tax can be computed, but 20% is ok.