No, there's no charge, just call CRO and ask them to add your request to your reservation. Be sure to list your most important requests first. For example, we wanted Arusha Rock Savannah and bunkbeds, but Arusha Rock Savannah was more important to me so I asked that it be listed first, then bunkbeds. We got Arusha Rock, but not the bunkbeds. We happened to be on Zebra Trail, too.