Zakat al- fitr is due after the month of Ramadan is over. Each Muslim must pay it on his behalf and for those whom he is duty bound to support. How it is paid, to whom, the amount and the time are all explained below.
This zakat is given its name because it becomes due when the month of Ramadan is over. It is not levied on property, but on heads and people. 
Ruling: Zakat al-Fitr is a duty incumbent on every Muslim. Ibn 'Umar reports: ‘Allah’s messenger made the Zakat al-Fitr, a sa'  of dates or barley, binding on every Muslim: slave or free, male or female, young or old.”
Conditions: Zakat al-Fitr is a duty that applies to all Muslims, whether they are young or old, male or female, as clearly stated in the hadith quoted above. It is also recommended to be paid for the unborn embryo if the pregnancy is past four months. People in the early period of Islam used to do so, as authentically reported to have been done by 'Uthman and others.
Every Muslim must pay it on his own behalf and on behalf of those whom he is duty bound to support, such as his wife and offspring. In the days of slavery, a master had to pay it for his slave. The Prophet (peace be upon him) said: ‘No zakat is payable on slaves except the Zakat al-Fitr.’ As a duty, Zakat al-Fitr applies to everyone who has more than what he needs for his food and the food of his dependants for the day and the night of the Eid. If one has in excess of that, which is enough to pay this zakat, then one must pay it. This means that there are two conditions for this zakat to be payable: 1) Islam. It is not paid by non-Muslims; and 2) having more than one needs for his essential needs for the day and night of the Eid.
Purpose: Zakat al-Fitr is made a duty as a condition to ensure a number of great benefits, such as:
1-It is a spiritual purification for the person who has completed the fasting in Ramadan. He might have slipped on occasions, committing some unintended errors.
2-It enables the poor and the needy to enjoy the Eid without having to ask anyone for food. They share the delight that the Eid brings to all people in the community. Ibn 'Abbas said: ‘Allah’s messenger stipulated Zakat al-Fitr as purification for the fasting person from any frivolous talk or obscenity and as a food for the needy.’
3-It is a demonstration of gratitude to Allah for enabling us to fast during the month of Ramadan and to offer night worship and do other good works in a totally blessed month.
What and how much
The amount due is four times the fill of a man’s cupped hands of wheat, barley, dates, raisins, dried yogurt, rice, corn, etc. which should be a staple food of one’s community. This is well established in a number of authentic hadiths, such as the one quoted above by Ibn 'Umar. A group of people may give their Zakat al-Fitr to one person, and one person may give his to a group.
Payment of the price of the food is not an appropriate alternative to giving the food itself, because paying the price is contrary to what the Prophet (peace be upon him) ordered and to the practice of the Prophet’s (peace be upon him) Companions. They used to pay it in kind. Moreover, Zakat al-Fitr is an act of worship required to be fulfilled with food, and it is wrong to give it in any different form.
This is the view of Malik, al-Shafi'i, Ahmad ibn Hanbal, Ibn Hazm and others. The Hanafi school of Fiqh and al-Thawri say that it is appropriate to pay the price of the same quantity of food. This is also reported to be the view of 'Umar ibn 'Abd al-'Aziz and al-Hasan al-Basri.
The scholars have discussed this point at length, Though ‘the permissibility of paying Zakat al-Fitr in value, rather than in kind, is indicated in the hadith that quotes the Prophet (peace be upon him): “Make them [i.e. the poor] self-sufficient on this day”, and this is fulfilled by paying the value as well as by giving food. it is best if possible to follow the Sunnah exactly by giving it as food. While this is easier and more feasible in our present time, particularly in industrial areas where people conduct all their transactions in money, the issue is not one of convenience. In many modern societies, the giving of wheat or dates may not be welcomed as this is not the staple used in their home. It appearsthat the Prophet (peace be upon him) stated that Zakat al-Fitr is paid in food for two reasons: 1) money was scarce among the Arabs at the time, which made it easier to give their zakat in kind; and 2) the purchase power of money differs from time to time, while a quantity of food meets a certain human need. During the Prophet’s time, food was easier to give and better for the person in need. If we can do the same without worrying that the food will be unwelcome or otherwise not useful for the person in question, that is certainly best. If we have doubts though, and find that the money will be more useful and welcome to the poor person, there should be no harm in giving it in value rather than in kind’
Some scholars of the Hanafi school of Fiqh say that it is better to give Zakat al-Fitr in kind at all times, because this complies with the Sunnah. Others give more details, saying that in times of hardship and scarcity of food it is better to pay this zakat in kind, but in times of plenty, paying it in money is better because it is more helpful to the poor.
Zakat al-Fitr becomes due when the sun has set on the last day of Ramadan, because this is what signals the end of the fast. The time to pay it is divided into two parts: the preferable one and the acceptable one. The preferable time is from the break of dawn on the Eid day until shortly before the Eid prayer. This is based on the hadith reported by Ibn 'Umar: ‘The Prophet (peace be upon him) ordered that the Zakat al-Fitr should be paid out before people go out to offer the Eid prayer.’ The acceptable time is one or two days before the Eid, as Ibn 'Umar and other Companions of the Prophet (peace be upon him) did that.
It may not be delayed until after the Eid prayer has been offered. If it is so delayed, it counts as an ordinary charity, and the person delaying payment is deemed to have committed an offence. The Prophet (peace be upon him) said: ‘For whoever pays it before the prayer, it is well and accepted, and for the one who pays it after the prayer, it counts as an ordinary charity.’ This type of zakat must be given only to the poor and needy.
The beneficiaries of zakat
Zakat is payable only to those who may benefit by it. These are the eight classes named in the following verse:
‘Zakah expenditures are only for the poor and for the needy, and for those employed to collect [zakah] and for bringing hearts together [for Islam] and for freeing captives [or slaves] and for those in debt and for the cause of Allah and for the [stranded] traveler - an obligation [imposed] by Allah. And Allah is Knowing and Wise.’
To give more details about these classes:
1-The poor: A poor person is one who does not have enough to meet his and his dependants’ needs of food, drink, clothes and home. He may have nothing, or may not have enough. He is given what meets his needs for a full year.
2-The needy: A needy person is one who gets half what he needs for living, or even more than half. He is given out of zakat funds what he needs for a year.
3- Administrative workers: This refers to anyone assigned by the Muslim ruler to collect zakat. The ruler gives him what he needs during his travel until he returns, even though he may be rich. This is because such a person devotes his time to this work. The administrative workers include all those who are given the tasks of collecting, recording, safeguarding and distribution of zakat to its rightful beneficiaries.
This certainly applied when Muslim governments undertook the collection and distribution of zakat, however, in modern times most, if not all, Muslim governments have abandoned this duty. However, there are many civil and charitable organizations which have taken on this responsibility and undertake this duty. These may deduct from what they collect of zakat money to pay to their staff, who are employed for this task. However, they may not pay zakat money except for their work in the administration of zakat. If a member of staff works only half of his working hours on zakat duties, while the other half is devoted to other aspects of his employment, he may be paid only half his salary out of zakat funds.
4-Those whose hearts are to be won over: These are people who may be unbelievers and they are given money out of zakat to win their goodwill towards Islam, or they may be Muslims but not very strong in faith, or they are people who have non-Muslim relatives who need to be encouraged to look favourably at Islam, or whose help is needed, etc.
5-The freeing of people in bondage: This refers to Muslim slaves who may be bought to give them their freedom. Their price may be paid out of zakat funds. Alternatively, a slave might have agreed a deal to buy his own freedom, and he or she is given what helps them to complete the deal and buy their freedom. This enables slaves to be good members of society, able to conduct their own affairs and to serve Allah’s cause as best as they can. The same applies to pay ransom to free Muslim captives taken by the enemy.
6- Debtors: This applies to a person who has incurred a debt for a legitimate purpose, whether it is for personal reasons or to help others. Debtors are given from the zakat funds what helps them to repay their debts. If someone incurred a debt to pay for the reconciliation of quarrelling parties, he is helped with zakat funds, even though he may be wealthy.
7- To further Allah’s cause: This applies to fighters for Allah’s cause who volunteer to join the Muslim army and they have no salary. They are given money from zakat, even though they may not be in need.
8- The traveller in need: This refers to a traveller who is unable to continue his journey to his place of residence. He may not be able to borrow what he needs, so he is given from zakat what he needs for his journey home.
 Al-Nadawi, Al-Fiqh al-Muyassar, p. 141.
 This is a measure equal to four times the capacity of an average man’s two cupped hands.
 Related by al-Bukhari, hadith No. 1,503; Muslim, hadith No. 984.
 Related by Muslim, hadith No. 982.
 Al-Nadawi, Al-Fiqh al-Muyassar, p. 141.
 Ibn Qudamah, Al-Mughni, vol. 3, p. 55; al-Bahuti, Kashshaf al-Qina', vol. 2, p. 287.
 Related by Abu Dawud, hadith No. 1,609; Ibn Majah, hadith No. 1,827; al-Hakim, vol. 1, p. 409.
 Ibn Qudamah, Al-Mughni, vol. 3, p. 60.
 Al-Qaradawi, Fiqh al-Zakat, vol. 2, p. 960.
 Related by al-Bukhari, hadith No. 1,503; Muslim, hadith No. 984.
 Related by Abu Dawud, hadith No. 1,609; Ibn Majah, hadith No. 1,827; al-Hakim, vol. 1, p. 568.
 Ibn Qudamah, Al-Mughni, vol. 3, p. 116.