The new "one-stop shop" for financial complaints only began a month ago, but it has already been flooded with more than 6,500 complaints.

Key points: The Australian Financial Complaints Authority received more than 13,000 phone enquires in its first month of operation

The Australian Financial Complaints Authority received more than 13,000 phone enquires in its first month of operation Most complaints have been about credit (45 per cent), followed by general insurance (21 per cent)

Most complaints have been about credit (45 per cent), followed by general insurance (21 per cent) The new authority says it is currently investing 84 issues that are definitely systemic

The Australian Financial Complaints Authority (AFCA) opened on November 1 and has average 310 complaints per business day so far.

The Federal Government first announced the new dispute resolution body in September last year, as it attempted to head off a royal commission into the banks and financial services sector.

AFCA has replaced three separate bodies — Financial Ombudsman Service, the Credit and Investments Ombudsman and the Superannuation Complaints Tribunal — and to date has experienced a 47 per cent increase in complaints received, compared to its predecessors.

While most complaints were made by individuals, AFCA said 460 were lodged by small businesses.

Banks top complaints to new authority

Banks were the most complained-about financial services provider, clocking up 2,367 complaints, followed by general insurers and credit providers.

AFCA said decisions made by financial firms were the main reason for complaints, including denial of insurance claims and attempts to borrow money.

Sorry, this audio has expired New authority in charge of dealing with finance related complaints

The authority received more than 13,000 phone enquiries during its first month of operation but 80 per cent of complaints were lodged online.

Eighty-four definite systemic issues are currently being investigated, along with four potentially serious contraventions.

"Systemic issues are identified in a complaint or several complaints, and have an affect on people beyond the parties to a complaint," said AFCA chief executive and chief ombudsman David Locke.

"Financial firms should be in no doubt that we will be referring and reporting these to the appropriate regulator."

AFCA predecessor grilled at royal commission

One of AFCA's predecessors, the Financial Ombudsman Service (FOS), has come under the microscope at the banking royal commission, sometimes for the wrong reasons.

The commission heard evidence of protracted processes for customers and small businesses who raised complaints through FOS, in some instances exacerbating the problems they were complaining about.

In one case, FOS ruled a grieving widow still had to repay loans within a short timeframe, despite finding Suncorp had been irresponsible in its lending to her husband, who was killed in a workplace accident.

Under questioning at the commission, a FOS representative admitted it was not the right thing to do in hindsight, considering the woman was offering to repay the loans over a longer period.

In its final annual report, FOS said it received 43,684 disputes in the 2017-18 financial year, an 11 per cent increase from the previous year.