The Australian Tax Office says it is investigating problems with its online systems after a flood of people seeking to lodge tax returns or apply for an early release of superannuation.
Social media has been abuzz at the start of the new financial year with criticism of the tax office, which has urged patience as people seek its services.
"We are investigating this as a priority, and our technicians are working to resolve the issue," an ATO spokesman told AAP on Wednesday.
Labor frontbencher Stephen Jones said the ATO should have known its systems would be in heavy demand at the end of the financial year.
"They should be designed to cope," he told AAP.
"People are already stressed and this has real life impacts - a delay in returns for people doing it tough."