Every Jew is obligated to give gifts to two needy individuals. All men, women and children over the age of bar mitzvah are obligated in this mitzvah, even if they do not have their own income, and even if they themselves would qualify to receive these gifts [1]. It has become customary for rabbis and other community leaders to collect funds on behalf of needy individuals. Monies can be given to these collections before Purim, provided the funds are distributed on Purim.
While there is a difference of opinion as to the exact minimum amount one can give to satisfy their obligation, (a few pennies or a few dollars), it is well known that the Rambam (Megillah 2:17) writes that it is better to increase the amount one gives to matanot l’evyonim even more so than for the Purim seudah or mishloach manot. Additionally, there is a custom that on Purim anyone who puts out their hand for assistance should not be turned away empty handed.
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[1] Mishnah Berurah 694:1
