Thin File
A thin file is a credit report with too little data for standard scoring — typically fewer than five accounts, or a history under six months. Nearly every newcomer to the US starts with a thin or empty file; secured cards, authorized-user status, and rent reporting are the standard ways to thicken it.
"No credit" and "bad credit" are different problems: a thin file means lenders simply lack evidence, and every early account carries outsized weight — good and bad.
Why it matters. With one or two young accounts, a single high-utilization month or one hard inquiry can swing the score 30+ points. The same events barely register on a 10-account, 10-year file.
How to thicken a file fast. (1) A secured card or a no-history-friendly starter card — see best cards with no credit history. (2) Becoming an authorized user on an established account, which imports its history. (3) Rent and utility reporting services such as Experian Boost — see how utilities and phone plans report. (4) For some nationalities, Nova Credit translates a home-country report for US issuers — see building US credit from India.
Example. A newcomer who stacks a secured card + authorized-user status in month 1 commonly reaches a usable 650+ FICO by month 6 — versus 12+ months with a single account.
Common mistakes: applying for premium cards while the file is thin (denials without score benefit), and churning starter accounts instead of letting them age. The full playbook: how to build US credit as a new immigrant.