Brisbane mother-of-two Tania Roberts and her husband Matthew are haunted by an unpaid energy bill.

In 2004 the couple moved house and asked TruEnergy to transfer their account to their new property.

They even continued as customers of TruEnergy at the new address for another year.

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"We continued to live and have an account with them and we assumed we were paying all our bills up to date," Tania said.

"We never heard anything more about this outstanding bill that they claimed that we had."

When the couple moved to Queensland there was no mention of any outstanding amounts when they finalised their account.

"It wasn't until five years later it comes up on my credit file," Tania said.

The black mark on Tania's credit rating was for $275, but the impact on her life was more taxing.

The bad credit rating was stopping the couple from buying a home, based on the blemished record and the banks simply did not trust them.

Paola Luz from Melbourne is another fighting to clear her name.

A computer error by electricity provider AGL has her owing $50.

"I paid the final amount, it was definitely in the system they even said so themselves," she said.

"Then I received a debt collector notice and there were I think two different amounts that they had."

Paola has been fighting for two years to have her clean record reinstated.

Damian Karmelich from credit reporting agency Dun and Bradstreet said up to 1.5 million Australians will have a black mark on their credit report.

"Bad credit can arise from any credit line you might be involved with ranging from something like a mobile phone all the way through to a mortgage and everything in between: credit cards, personal loans, car loans," he said.

"Any type of credit facility these days is applicable to reporting on a credit report."

Damian said 86 per cent of Australians with credit arrangements have never checked their history so most of us would have no idea if we have a black mark.

Nicole Rich from the Consumer Action Law Centre said it is not only important to know what is on your credit report but also your rights when it comes to clearing it up.

"There can sometimes be smaller types of debts on the report that we don't think should always be on there," she said.

"You can see really nasty things like very small debts maybe from a video store or even from a doctor's surgery."

Concerned by the growing number of black listings, Dun and Bradstreet have now set up a credit report website, where you can check your rating free.

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