My husband is not the biological father to my son but he is on the birth certificate does he have the right to claim my son on his taxes?

If you were married to your husband whwn the child was conceived and born, I believe the law considers your husband to be the father regardless of who the biological father is.

That being the case, your husband CAN claim him if he provided more than half of his total support.

The person who has the right to claim the child as a dependent for tax purposes is the custodial parent. So if your son lives with you, and you are his custodial parent, then either you or your husband could claim the son. The fact that your husand is listed as the father on the birth certificate makes it pretty difficult for anyone else to claim that he is the father, and even if they did, the fact that you are the custodial parent trumps the ability of the biological father to claim him.

ebaines raises a good point about custody that I forgot to mention. Good catch!