I live in Ohio and have a 7 yr. old daughter. Her father only pays support and doesn't see her. We have letters from him stating that he never wanted her and does not wish to have a relationship with her. I am married now, and my husband is the only father figure she has known. My daughter wants to change her last name to my married name. Is this possible to do without my husband adopting her? Do we have to get biological fathers consent?

If you have the legal father's (biology is irrelevant in this case) consent you can change her name to anything you wish, regardless of adoption.

If the legal father resists, you will have an uphill battle that will likely lead to failure or at least compromise (hyphenated names are common in this case). He does not appear to care one way or another, so if he resists, remember the mantra... money talks.