Whosoever dies from amongst the (المكلفين) those that are bound by the legislation, whilst not praying, then he is a disbeliever. He should not be washed, he should not be prayed over, he should not be buried in the graveyards of the Muslims, and his next of kin do not inherit from him, rather his wealth should go to the treasury (بيپ المال) in the most correct opinion of the Scholars; because of the saying of the Prophet sallAllaahu ‘alayhi wa sallam in the authentic hadeeth:
بيپ الرجپ وبين الشرپ والكفر ترپ الصلاة
Between a man and polytheism and disbelief is the abandonment of the prayer.
And his saying sallAllaahu ‘alayhi wa sallam:
العهپ الذي بيننپ وبينهم الصلاةپ فمپ تركهپ فقپ كفپ
The covenant that is between us and them is the prayer so whosoever abandons it the he has disbelieved. 
‘Abdullaah bin Shaqeeq al-‘Uqaylee, the respected Taabi’ee may Allaah have mercy upon him, said:
پ The companions of the Prophet of Allaah sallAllaahu ‘alayhi wa sallam never saw anything from amongst the actions, the abandonment of which is disbelief, except the prayer.پ
And there are many hadeeths and statements with this meaning.
And this is regarding the one who abandons it out of laziness and does not reject its obligation, and as for one who rejects its obligation, then he is a disbeliever, apostate from al-Islaam with all of the people of knowledge.
We ask Allaah that He rectifies the condition of the Muslims, and that He makes them traverse upon His Straight Path, Indeed He is the All Hearing the Responsive One.
 Reported by Muslim in his Saheeh.
 Reported by Imaam Ahmad, and the authors of the Sunan with a authentic chain from the hadeeth of Buraydah may Allaah be pleased with him.