After taking antibiotics for a uti how long do you have to wait to have sex?

No rule about that: You can have sex again immediately after treating the uti. Be sure to drink lots of water, and try to urinate before and after sex to flush out any bacteria that might have settled there. Cranberry tablets are helpful for preventing utis. Also maintaining a healthy vaginal bacterial balance is helpful. You can look for vaginal probiotics at whole foods.

UTI vs STD: Just clarifying that your asking about sexual activity after treatment for a UTI (and not an std), right? And voiding after intercourse is more important than voiding before activity. (in cases of an std, there should be no "activity" until after both ("all") parties have been treated.).