Australia Post's online services have been intermittently unavailable since late Sunday evening, preventing business customers from being able to label, ship, and track items.
The problems stem from intermittent errors with AusPost's digital services application programming interfaces (APIs), which for unknown reasons return 401 unauthorised request error codes.
Shipping and tracking APIs including pricing, label printing, and lodgement are running with degraded performance. Western Union transfers are also affected.
The services have experienced ongoing problems since October 16.
Managing director of fashion firm Costume Collection, Vilay Malaykham, told iTnews the outage has prevented more than 500 customer orders for Halloween from being labelled, and therefore mailed out.
Malaykham said he fears the backlog could swell to over 1500 orders unless the problem is fixed.
An AusPost spokesperson confirmed the issue and said it could be remedied by resending API requests, which the spokesperson assured would not result in a duplicate process.
The postal body is investigating the issue but would not provide detail on the cause.
More to come