The Banking Ombudsman Scheme is being expanded so it can deal with disputes involving non-bank businesses that also take deposits.
The Government has approved expanding the scheme to include other businesses like finance companies, building societies and credit unions.
Under the new Financial Services Providers Act, all providers must belong to an approved dispute resolution scheme by the end of the year.
To participate, the businesses must be regulated by the Reserve Bank and have a minimum double-B credit rating.
The Banking Ombudsman chair, Ron Paterson, says the scheme has the advantage of knowing its industry and having a solid reputation.