Short answer
How does a credit dispute letter work?
A credit dispute letter asks Equifax, Experian or TransUnion to investigate one specific item you believe is wrong. Under the Fair Credit Reporting Act the bureau generally has 30 days to investigate, and must correct or delete information it cannot verify. Name the account exactly, say what is wrong and why, attach copies (never originals) of your proof, and send it by certified mail so you have a date. Disputing accurate information will not remove it.
Paid once. Editable DOCX and PDF. Not legal or credit advice.