The letter was placed inside the family's letterbox without a return address or any identification to assist with tracking down the writer.
So the parents instead took to Facebook to explain that they had tried to find the right neighbour to apologise for their children's behaviour.
'I was devastated to know we had upset our neighbours and went to visit them to apologise personally with my children,' the person wrote, adding that their young son has a condition that makes him a 'little louder'.
'Unfortunately, they said they didn't write the letter and said they don't have any problem with noise coming from our house'.
The parent also shared that they had been trying to get the kids outside more and away from devices/screen time.
'I cannot visit every house in the street, so I hope you read this. I wanted to let you know that we are sorry,' the post said.
Online support
The parent's post was met with immense support, with many users commenting that the author of the letter should have spoken with them in person instead.
'Congratulations on being a considerate and kind part of society. More so for being a beautiful parent. Keep doing what you feel is right for you and your children. Kids don't come with a manual. All we can do is our best,' one person wrote.
Another user referred to the writer of the letter as a 'gutless moron'.