Zakaat ul-fitr is a fard (obligation) for those capable of giving it. This is stated clearly in the hadeeth of Ibn `Umar ():
"Allaah's Messenger has ordained zakaat ul-Fitr, in the amount of one saa`1 of dates or one saa` of barley, for the Muslims - slave or free, male or female, young or old; and he ordered that it be given before the people went out to the (`Eed ) prayer."2
This hadeeth further indicates that it is an obligation for every (capable) Muslim individual, regardless of age or social status.
The responsibility of giving out zakaat ul-fitr falls upon the head of the household; he should give it on behalf of himself and those under his care: young and old, male and female, free and slave. Ibn `Umar (t) said:
"Allah's Messenger ordained sadaqat ul-fitr for those under your custody: young and old, free and slave."3As for the person who does not have the financial ability to give it, he is exempt because of general texts in the Qur'aan and Sunnah, such as Allaah's (SWT) saying:
Allaah does not require from any soul more than its capacity ...4
And the hadeeth narrated by Abu Hurayrah:
When I give you a command, do as much of it as you are capable.5
Some scholars further require that it be given on behalf of a fetus. However, there is no evidence for this; and the fetus is not considered to be a young person - neither in the language nor the common understanding of people.