Custom is an accepted way of behaviour or doing things in a society or community. It can be a practice, a habit, a way of living or performance. Usually when learned men do something, others follow the same.
Customs begin when a society recognizes a set of rules intended for its common benefit. High-quality thoughts, ideologies and conduct rules are thus made customs through continuous practice and precedence. Customs teach mankind how to lead a life filled with truth, kindness, duty, love, devotion and affection. When these customs get the backing and support of religions they become unbreakable. These noble virtues are enabled him to watch and follow rules and rituals of neighboring locality/country and accept whatever practices are good for his community. Hence, the desire of the people to keep such belief and practice without error and omissions will persist.
The known earliest mention about Muslims of Kerala is in the Quilon Syrian copper plates of 9th century CE, granted by the ruler of Kollam. Kerala had trade relations with Arabia even before advent of Islam..Early days the king's encouraged conversion to Islam since it means more business with Arabia and more money. They even provided with resources to practice Islam in Indian soil.

Barath

According to Muslim belief, barath is the day in which Allah (God) distributes food grains to the people. Muslims celebrate the day as an important one as Hindus celebrate Vishu.

Chelakarmam

Chelakarmam is the circumcision ceremony among Muslims. It is also known as Sunnath, Markkakalyanam etc.

Ehramkettu

Muslim pilgrims to Mecca used to wear white clothes that do not have stitches. Wearing of this cloth is known as Ehramkettu.

Hajj

The hajj is one of the two pilgrimages to Mecca required by all Muslims. All healthy adult Muslim men and women should perform it at least once in their lifetime if they have sufficient means. The Hajj is to be performed during the first half of the month Dhu al Hajja. Those who performed Hajj use honorific title Hajiyar.

Ka-aba Pradikshinam

Ka-aba Pradikshinam is a ritual performed by Muslims in connection with Hajj pilgrimage to the Holy Mecca.

Kabaradakkam

Kabaradakkam is the rituals connected with the burial of dead body in the mosque. Soon after death, the dead body is laid in such a way that the legs are turned towards Mecca. The dead body after washing covered with a white cloth. Mulla from the mosque then chants verses of Quran. Then the body is taken to the mosque in a plank specially provided for the purpose. After prayers, the body is laid in the burial pit and the relatives pour mud over the body by chanting verses of Quran. On completion of the burial, a stone each is placed on the head side and leg side.

Kalima

The Kalima is the chanting of "La ilah illa Allah wa Muhammad rasul Allah", which means that there is only God and Muhammad is His prophet. It is also uttered as part of the Muslim call to prayer.

Khathuba

Khathuba is the sermon delivered by the Khatheeb (the leader who leads prayers) before the ommencement of Friday sermon in the mosque.

Nikkah

The marriage of Muslims is known as Nikkah. There are very few differences on the rituals of Nikkah between the Muslims of North Kerala and South Kerala. The first ritual is the fixation of date and time of marriage. On the day before the marriage, there is another rite known as Kalthi. The marriage is formally registered at this function. The marriage takes place in bride's residence. Tying of thali, exchanges of rings are also performed. Oppana is a special item. The bride's parents send sweets and fruits to the bridegroom’s house and vice versa.

Nikkah

Valayidal (Wearing the Bangle) The Muslim marriage ceremonies start with the “Valayidal” ritual in which the groom’s mother gifts the bride with a set of gold bangles. More than just a ceremony, it means lifelong commitment also. It shows the groom’s mother’s acceptance of the bride to her family, as her son’s bride.

Naal Nischayam (Date Fixing)

After the “Valayidal” ceremony, elders of the family gather at the groom’s house to fix the date of the marriage.

Mehandi Function

It is an inevitable part of Muslim marriages across Kerala where Mehandi experts adorn the bride’s hands and feet. It is also called “Mailanchiyidal”. The function is held at bride’s house in the presence of family and friends with social entertainments like oppana and Mappilapattu (traditional song of Muslim community).

Niskaram

Niskaram is the five obligatory daily prayers, which is also known as namaz. The prayers are performed before sunrise, at noon, in the mid-afternoon, immediately after sunset, and at night between 8 and 9 O'Clock. Niskaram is also associated with a specified set of positions, such as standing, bowing, and prostrating. On Fridays, Niskaram is to be performed in the mosque.

Noyambu

Noyambu is the fast prescribed for healthy, adult Muslims during the 30 days of Ramadan month. From dawn until dusk, no food, drink, or sexual relations are permitted. Patients and feeding mothers are exempted from fasting, but they are expected to make up for missing the fast at other times.

Oathu (Chanting)

Study of Qur'an in the mosque is known as Oath. Arabic language is also taught as a part of Oath.

Thalaq

Thalaq is the procedure of divorce prevailing among Muslims. Before a divorce came into effect, the husband would make statement for three times in the presence of witnesses. Before saying Thalaq certain conditions are to be fulfilled. After divorce the couple cannot remarry each other unless the wife marries another man and is widowed or divorced again.

Nikkah

The marriage of Muslims is known as Nikkah. There are very few differences on the rituals of Nikkah between the Muslims of North Kerala and South Kerala. The first ritual is the fixation of date and time of marriage. On the day before the marriage, there is another rite known as Kalthi. The marriage is formally registered at this function. The marriage takes place in bride's residence. Tying of thali, exchanges of rings are also performed. Oppana is a special item. The bride's parents send sweets and fruits to the bridegroom’s house and vice versa.

Umrah

Umrah is also a pilgrimage like Hajj. Muslims perform this with the rituals of Ehramkettal (wearing of un-swen cloth), Thavaf (rounding of Ka-aba), walking between Safa and Marva for seven times. Unlike Hajj, Umrah can be performed at any month.

Zakat

The zakat or alms tax is levied annually and distributed to the poor to be essentially performed by a Muslim.