A hard inquiry you never authorized can shave points off your score and may be a sign of fraud. If you didn't apply for credit, you can dispute the inquiry under the FCRA.
A hard inquiry happens when you apply for credit — a loan, card, or mortgage — and it can lower your score slightly. A soft inquiry (checking your own credit, pre-approved offers, employer checks) does not affect your score and isn't visible to lenders. Only hard inquiries you didn't authorize are worth disputing.
Note: you generally cannot remove a legitimate inquiry from credit you actually applied for, even if you regret applying. Hard inquiries fall off automatically after about two years.
Identify the inquiry on each report and note the company name and date. Then dispute it in writing with the bureau reporting it, stating that you did not apply for or authorize credit with that company. Under 15 U.S.C. § 1681i, the bureau must investigate; under § 1681b, a company may only pull your report with a permissible purpose. If there was no authorization, the inquiry should be removed.
Multiple unfamiliar inquiries often mean someone is applying for credit in your name. Place a free fraud alert or credit freeze with each bureau, and file a report at IdentityTheft.gov. Then dispute both the inquiries and any resulting accounts.