Ten Canberra childcare centres and a family daycare provider investigated by authorities were found in breach of national standards for issues including poor staffing arrangements and allegedly harming or losing children.
Nineteen of the 51 complaints investigated by the Education Directorate's Children's Education and Care Assurance team in the 2016-17 financial year established a breach of national laws.
Almost 40 compliance actions were handed out by the authority in the same year.
"Compliance actions range from administrative letters, to conditions on service or provider approval, compliance directions, compliance notices, suspension of services and prohibition of individuals," the directorate's annual report said.
The Education Directorate would not name the providers involved nor provide further detail on any incidents. A spokeswoman confirmed the prohibition notice was still in play.
"We cannot name the providers until we have settled a new publication policy in consultation with the sector," she said.
"We cannot provide copies of prohibition notices as it applies to individuals, however we can advise that no prohibition notices have been lifted."
Productivity Commission data published earlier this year showed Canberrans forked out the most for child care provided by the nation's least qualified staff.
The same report found the ACT had the highest proportion of children aged up to four years old admitted to hospital while in care, with 3.5 per cent of injuries occurring in an early childhood care setting compared to 2.9 per cent nationally.
Early Childhood Australia chief executive Sam Page said the ACT's figures were "disappointing", adding "any breach is disappointing".
"It is a continuous quality improvement exercise ... and we do know there are some workforce issues in the ACT that really need to be dealt with," she said.
"There are workforce shortages in the ACT. I think we need to do more to encourage people to consider early childhood education as a career.
"We need to address wage disparity between people with similar qualifications working in early childhood and in the school sector."
Children First Alliance co-chair Amanda Tobler, representing 10 ACT early childhood education and care providers, noted that almost 90 per cent of staff working in early learning centres in 2016 had an early education and care qualification.
"As early childhood education and care providers, we are always working to improve our work," she said.
"To support this, the Children First Alliance is calling on the ACT government to support ongoing professional development by providing funding for an early childhood education and care professional development fund in the next budget."
The Education Directorate's annual report showed the ACT had 354 early childhood services approved as at June 30 this year.
Of those, 308 services had been awarded a quality rating, representing 87 per cent of services.
Three services ranked as "significant improvement required" and 100 were working towards a quality rating. Two-hundred-and-five were excellent, meeting or exceeding standards.
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