Consumers can make complaints about financial services to the informationofficers on IFSRA's 1890 lo-call phone line.
The new financial regulator promises to act as a single port of call for consumers who feel they have been ripped-off on a financial product or misled by financial advice.
Launched last week, the centrepiece of the Irish Financial Services Regulatory Authority's one-stop shop is its lo-call number for consumers: 1890 777 777.
"This is the one-stop shop we have been seeking for consumers," said the Tánaiste, Ms Harney. "There is now one place for their queries. No more confusion, no more split roles, no more falling between stools."
However, IFSRA is not fully up and running. The Department of Finance has yet to publish a second Bill that will give it the power to appoint a statutory financial services ombudsman and finalise how its complaints-handling system will work.
Consumers can make complaints to the information officers at the end of IFSRA's 1890 lo-call phone line, but most of these complaints will continue to be channelled back through the old system.
A spokesman for IFSRA said the phone line had been "busy enough" so far. Any complaints made would be logged, he added.
If any patterns emerge, then IFSRA may launch an investigation into a particular company or product or use the information to shape new codes of practice.
But most individual disputes that cannot be resolved between the consumer and the institution or firm concerned will be referred back to the relevant voluntary ombudsman scheme.
At the moment, if consumers have problems relating to a bank or building society account, including mortgage agreements, the Ombudsman for Credit Institutions, Mr Gerry Murphy, may investigate, while the Insurance Ombudsman, Ms Caroline Gill, deals with complaints about insurance companies.
This system will continue until legislation allowing for the appointment of the statutory financial services ombudsman is enacted. It is then expected that the two voluntary schemes will be represented on a council supporting the statutory ombudsman.
IFSRA's interim board has also proposed that consumers should have to leave their complaint with the relevant ombudsman for a period of 12 weeks before approaching the statutory financial services ombudsman.
The IFSRA spokesman said it was "very difficult to make detailed comment" on how the system would work until the publication of the Bill, expected later this year.
"In the meantime, we, as IFSRA, did not want to set up on day one and not have a service that's directly accessible by consumers, regardless of the legislative powers we have," the spokesman said.
"We need to be realistic in what we can deliver from day one. We can't deliver everything," he said.
The remit of the Office of the Director of Consumer Affairs to handle complaints about mortgage brokers has now been transferred to IFSRA, which has also assumed the Central Bank's regulatory powers over investment intermediaries.
Last week, the chief executive of IFSRA, Mr Liam O'Reilly, singled out the selling of the new personal retirement savings account (PRSA) pensions as one of the first issues that he would examine. The regulator is planning a public information campaign on the new pensions.
However, the handling of complaints relating to PRSAs will be split between IFSRA, which will investigate complaints about potential mis-selling, and the Pensions Ombudsman, Mr Paul Kenny. Mr Kenny opens his doors to complaints relating to the poor administration of pension schemes in July.
IFSRA is set to establish a new drop-in centre for consumers in premises near but separate to its current location within the Central Bank on Dame Street in Dublin. The regulator is also considering how it will meet the needs of consumers outside Dublin.
According to IFSRA's communications officer Ms Karen O'Leary, it is advice and information that most consumers need.
"The complexity and range of financial products in the market are so vast now, that consumers are at a severe information disadvantage and this carries obvious risks because the institutions will always know more than their customers," she said.
According to Ms O'Leary one of the most basic mistakes people make is to not shop around for a more competitive product and to not alert the business to their dissatisfaction. Administrative errors from a bank or lender can also lead to unnecessary confusion.
Ms O'Leary continually reminds consumers that they are entitled to know their own credit history by checking the database of the Irish Credit Bureau.
"These are basic information resources that most people don't know about but they can make a huge difference if a problem arises with a financial institution," she said.