Research shows that both utterance type and rapport‐building can affect children's productivity during the substantive phase of investigative interviews. However, few researchers have examined the effects of utterance type and content on children's productivity within the rapport‐building phase. In the present study, transcripts of interviews with 94 4‐ to 13‐year‐old alleged victims were examined. Interviews were conducted using either the National Institute of Child Health and Human Development (NICHD) Protocol or the Memorandum of Good Practice (MoGP). The NICHD Protocol interviews contained more invitations and questions about events and hobbies/likes than the MoGP interviews. Children's productivity was associated with utterance type and topic, showing both the benefits of invitations and questions asking about past events. Our findings complement research focusing on the substantive phase of child forensic interviews, suggesting that both utterance type and prompt content during the rapport‐building phase can affect children's immediate productivity. Copyright © 2016 John Wiley & Sons, Ltd.