It has inadvertently shared emails around the people making the applications, including details on children’s names, their schools, dates of birth, parents’ earnings, national insurance details and banking information.
A council spokesperson said: "Unfortunately due to a procedural error, personal information was shared with third parties and we have apologised and informed everyone concerned.
"The breach has also been reported to the information commissioner and new procedures are in place to prevent a re-occurrence."
DistressThe Herald has reported that one of the parents said she received 30 emails in two batches containing applications for the clothing grant, causing her considerable distress. She immediately contacted the council, which did not seem to be aware of the mistake at the time.
The woman, who has remained anonymous, said: "I didn't like having the pressure of knowing I have all these people's details that weren't for me either.
"It made me concerned about how often these types of things happen, and I don't know how well they handle people's details now.
"It's really concerning. Some of the applications had as many as six children on the forms."