The inquiry, announced in July 2014 by then Home Secretary Theresa May to investigate institutional failings that came to light in abuse cases involving high-profile public figures, said it is "very concerned" by the absence of professional registration for those working in care roles in children's homes in England.
It has called for the Department for Education to introduce arrangements for the registration of staff but concedes that this may require a period of phasing in, so has said that professional registration of children's home managers should be prioritised.
"Children's homes in England must be registered with Ofsted and those working in care roles are expected to have a minimum level of qualification," the interim report states.
"But there is no requirement for individual care workers, other than social workers, to register with an independent body charged with raising standards within the profession and supervising their fitness to practise.
"Regulation of a care setting by an independent inspectorate complements effective professional workforce registration ? it does not replace it."
The report said registration should be with an independent body charged with setting and maintaining standards of training, conduct and continuing professional development, and with the power to enforce these through fitness to practise procedures.
In total the report makes 18 new recommendations. These include calling for all police officers who want to progress to chief officer rank requiring operational experience and accreditation in preventing and responding to child sexual abuse.
The inquiry also wants the Department of Health and Social Care to develop a national policy for the training and use of chaperones in the treatment of children in healthcare services.
Meanwhile, it has called on the National Police Chiefs' Council to ensure that complaints relating to child sexual abuse are no longer "disapplied" by police forces on the grounds that the incident took place more than 12 months before the complaint was submitted.
And it wants the Ministry of Justice to provide primary legislation to
give victims and survivors of child sexual abuse in civil court cases the same protection as vulnerable witnesses in criminal court cases.
Professor Alexis Jay, chair of the inquiry, said: "The inquiry has a significant programme of work under way.
"We have held five public hearings and eight seminars. We have published the findings from two hearings and many research reports. Over 1,000 victims and survivors have now participated in the Truth Project.
"The interim report draws all this together and provides a clear account of our work so far. It sets out the key themes emerging from our work and where the panel and I identify changes which we think will help better protect children, we say so.
"We have much work still to do and evidence to hear - we will hold a further eight public hearings in the next 12 months alone, but we are making good progress."
"I indicated in December 2016 that I expected the inquiry to have made substantial progress by 2020. I believe we are on target to do that and to make recommendations which should help to ensure that children are better protected from sexual abuse in the future."
The inquiry has so far held five public hearings and seven seminars and published reports setting out the findings from two public hearings and nine research reports.