“It’s All Sorted” Means “Everything Is Arranged”

In everyday Australian English, ‘It’s all sorted’ usually means that arrangements are complete or a problem has been dealt with. It does not merely say that objects have been placed into categories.

‘Have we got somewhere to stay on Friday?’ ‘Yep, it’s all sorted.’ The reply means the accommodation is confirmed and the other person need not worry about it. Sorted can also stand alone as a brief confirmation: ‘Tickets?’ ‘Sorted.’

This use is also common in British English and is not uniquely Australian. Its tone is relaxed and confident. In a formal email, Everything has been arranged may fit better. For literal classification, name the object: I sorted the files by date.

https://dictionary.cambridge.org/dictionary/english/sorted
https://www.oxfordlearnersdictionaries.com/definition/english/sorted