Staff at Towerlands Cottages Nursery and Schools Out Club breached procedures which require parents or carers to provide a password to collect a child.
The service was given the second lowest possible grade by the Care Inspectorate in a snap inspection.
The report states: "Staff could not determine who was arriving to collect the children from the out-of- school care service."
The service, in Irvine, North Ayrshire, was rated 'weak' for quality of care and support, quality of environment and staffing and 'unsatisfactory' for management and leadership.
However, in the report on the inspection, inspectors noted that legal requirements for improvement made at a previous inspection had been met.
New risk assessments have been developed for the collection of children from the out-of-school service, outlining instructions for staff. The manager has also written to the council asking for the CCTV system to be re-instated.
However, the service was ordered to put a new system in place to enable staff to determine who is collecting a child.
The facility is run by East Irvine Nursery and After School Care Ltd (EINASC) .
The service operates from two premises in Bourtreehill, Irvine and provides care for children from birth to school age.
A spokesman for the Care Inspectorate said: "Where we have concerns about a service we don't hesitate to act and we are pleased to note that legal requirements for improvement made at an earlier inspection have been met.
"However, further improvements are needed and we continue to work with this service to ensure the care provided meets the standards we expect."
It comes after an after school care service in Glasgow's West End was closed down following a series of damning inspections.
The Care Inspectorate raised "serious concerns" about Thornwood Out of School Service, including a failure by the owner to have the relevant insurance to run the service.