Six-hundred million dollars is what false billing scams are costing the small business sector, the Australian Competition and Consumer 2011 Target Scams report has unveiled.

False billing scams target small businesses to trick them into paying for unwanted or unauthorised listings or advertisements in magazines, journals, business registers or directories. Common scam tactics are to send a business a subscription form disguised as an outstanding invoice to get the business to sign up for unwanted ongoing advertising services.

ACCC deputy chair Michael Schaper said while businesses are aware of the threat of scams, with the amount down from almost $1 million in 2010, the ACCC is still very concerned that around one in six small businesses that report this activity have lost money to scammers.

"In a wired world of smartphones and apps, it is easy to overlook low tech methods of scamming. But often the simplest scams can be the most effective. A false invoice that is not checked can end up being very damaging,” he said.

The most popular small business scams involve false billing, business directory, faxback and office supply.

The ACCC has taken action against a number of traders allegedly involved in misleading and deceptive, or scam-like conduct targeting Australian small businesses. Following ACCC action, in April 2011 the Federal Court imposed penalties totalling $2.7 million against two overseas companies, Yellow Page Marketing BV and Yellow Publishing Limited, for sending thousands of Australian businesses misleading faxes and invoices.