Current year unused leave (up to 15 days) can be carried forward for 1 year until following year 31 Dec, afterwhich, if still not consumed will be forfeited.
Staff who took more than 15 days is because they have carry forward leave from previous year. HRIS has been set according to the leave policy and as such will not allow them to apply urgent leave/vacation leave if they do not have the entitlement/balance leave.