The commission says the prosecution is its most significant action in the car finance sector ever and involves seeking pecuniary penalties.
Go Car Finance is the New Zealand subsidiary of Australian company Solvar, which is publicly listed on the ASX.
Second Chance Finance is wholly owned by another New Zealand company, which is owned by Maseeh Ul Amin.
The prosecution, set to be filed in the High Court in the coming months, will allege the companies breached their obligations under the Credit Contracts and Consumer Finance Act (CCCFA).
Specifically, the ComCom alleges the companies failed to assess whether consumers could afford their loans. In respect of Second Chance Finance, the commission also alleges this company breached its record-keeping obligations.
"In our view, both lenders have not been appropriately assessing loan affordability when making car finance available. Our legal action will address the potential for these lenders to have caused substantial financial hardship to Kiwi consumers," Unger said.
"For the first time, we will be seeking pecuniary penalties from the High Court for these alleged breaches.
"We are also seeking orders for the lenders to pay statutory damages to named borrowers as well as the waiving of any outstanding amounts owed by borrowers where their vehicles have been repossessed."
- Ethan Griffiths, Open Justice reporter