The ATO, supported by NSW and Federal Police, has made surprise visits to over a dozen sites across Sydney as part of an investigation into potentially fraudulent phoenix activity.

Recent figures show that phoenix activity costs the Australian economy up to $3.2 billion each year.

Honest businesses suffer the most, losing almost $2 billion in unpaid debts and the non-supply of purchased goods and services.

The ATO said that, if a member of the public has any knowledge or concerns about companies that may be exhibiting phoenix behaviour, they can report it online at ato.gov.au/reportaconcern or by calling 1800 060 062.