The charity has also noted an increase in the number of younger children they help in some areas and a big increase in the number of children reporting sexual exploitation in Wales.
Of 546 sexually exploited children who Barnardo’s worked with in September, the number known to be trafficked rose by 84 per cent, from 76 to 140 year on year.
That equates to one in four in the UK, up from one in six in 2011, and rising to one in two in Wales.
The number of sexually exploited children known to Barnardo’s rose by 22 per cent to 1,452 in the UK last year and 37 per cent during the past three years.
Barnardo’s Chief Executive Anne Marie Carrie said: “We are shocked at the rise in the number of children reporting they have been moved around the country by abusers.
“Domestic trafficking of children for sex is a sophisticated type of exploitation, a sinister form of organised violation through networks of criminals.
“Nobody currently knows the full extent of these crimes because of their hidden nature, but what we do know is that every time we open a new service for victims it quickly becomes fully subscribed.
“If we are to save children from suffering for years at the hands of their abusers, more must be done by the authorities to identify victims of child sexual exploitation who are being internally trafficked and to stop this activity earlier on.”
The charity surveyed 23 of its specialist services, an annual report it compiles each year.
Barnardo’s service data also revealed that numbers of sexually exploited children helped by the charity rose by 377 per cent in Wales, from 22 to 83, where the charity has become more active.
Three services, in the north east, south east and Northern Ireland, noted an increase in the number of younger children they helped, with children as young as seven meeting strangers on the internet.
Barnardo’s called for the government and the devolved administrations to protect victims and other children from being trafficked for sex, and for the Department for Education and the Home Office to do more to tackle child sexual exploitation in England.