REG FIN on a credit report: finance company loan
REG FIN is probably a loan from a finance company: on reports, "FIN" usually stands for finance or financial.
How to find out which company reported REG FIN
Your free report at AnnualCreditReport.com shows the full name and address of whoever reported REG FIN; our guide to identifying a creditor covers the other ways to find out.
Verified pages for similar report codes
Verified pages for other codes that start with "REG" (not necessarily the same company as this one):