Okay so there's different views regarding this. To be honest I haven't celebrated my birthday since I was 9 or 10. But sometimes my family likes to go out for dinner when a member's birthday comes.
I'll be posting two fatwas on this.
The first one:
What is the ruling on celebrating birthdays?
If you mean formally celebrating the likes of the birthday of Prophet Muhammad (peace be upon him) or Prophet Jesus (peace be upon him) as a devotional act, then this is clearly unlawful. Such festive days are newly contrived innovations that conflict with the dictates of Islamic Law.
Such rites are from the traditions of the People of the Book. They have a devotional purpose and are carried out seeking nearness to Allah. This is the reason I view such occasions to be unlawful and prohibited.
If, on the other hand, you mean celebrating personal birthdays, then this is something different, since it is not intended as a devotional act or an act of worship. Therefore, it is not as serious a matter.
Still, personally I tend to regard it as something disliked for people who are not already accustomed to celebrating this event in their culture, but do so merely to blindly ape cultural practices that are outside of their own experience and understanding.
All the same, birthday parties are not religious occasions and do not have an overtly religious cast to them.
A birthday party is not a festival of the nature of an `îd that is a general festive day for the entire community. It is merely a personal occasion that means nothing more than a remembrance of something dear. Therefore, it is permissible.
And Allah knows best
And the second one from: http://askthescholar.com/question-details.aspx?qstID=6658
I am 21 years old. I don't celebrate my birthday with birthday parties. But is it acceptable in Islam if I invite some friends and relatives of mine and treat them with food without telling them that the foods are for my birthday? To what extent celebrating birthday is haram in Islam?
Celebrating birthdays has been a contentious issue among scholars: While one group opposes it, others approve of it as long as one refrains from all objectionable rituals and practices. Those who approve of it are basing on the principle of jurisprudence, which states that customs cannot be deemed as haraam unless forbidden by Shari'ah; or unless there are evils associated with it. The case is different with religious rituals and beliefs, which can never be instituted except by the clear sanction of the Law-Giver.
In light of light of the above, if it is a custom in your culture or country then you may do it as long as you stay away from the following: 1. Wastage and extravaganza; 2, Music and un-Islamic rituals and practices. In case of celebrating the birthday you may do well to give thanks to Allah by giving charities to the poor, and reading some Qur'an and offering du'as and supplications.