Question: A person went to sleep before the sahoor in Ramadhaan whilst having the intention to take the sahoor. But, he slept through ’til the morning. Is his fast correct or not?
Response: His fast is correct because the sahoor is not a condition for the correctness of the fast. Rather it is preferable, for that which the Prophet (sal-Allaahu `alayhe wa sallam) said ((Take the sahoor for certainly in it is blessing)). (This hadeeth has been) agreed upon by al-Bukhaaree and Muslim.
Shaykh Ibn Baaz
Fataawa Ramadhaan – Volume 1, Page 185, Fatwa No.124;
al-Fataawa libni Baaz – Kitaab ad-Da’wah, Volume 2, Page 161.fatwaonline.com