How to dispute a debt in writing (within 30 days)
You have the right to demand proof before you pay. Use it — in writing, within 30 days of first contact.
Education only. Not legal advice, not a determination of your rights, and not a recommendation to take any action. Facts, contracts, deadlines, and current law can change the outcome. For your situation, talk to a qualified professional.
Your 30-day right
Within 30 days of a collector’s first contact, you can dispute the debt and ask for validation. If you do, the collector generally must stop collection until they send you proof — like the original account information and the name of the original creditor.
What to ask for
- Proof that you owe the debt.
- The original creditor’s name.
- The balance and how it was calculated.
- The California Debt Collection License number (collectors must be licensed and must print it).
How to send it
Mail your letter by certified mail with return receipt. Keep copies. Mark your calendar for the 30-day date. After that, if they cannot prove it, they cannot enforce it by pressure.
If the debt is old
If the debt is more than 4 years old (in California, for most written-contract debt), the lawsuit window may be closed. Paying or acknowledging an old debt can restart the clock in some cases — get free legal advice before you pay.
Official sources
- CFPB — I don’t think I owe the debt
- FTC — Debt Collection
- CFPB — How do I dispute a debt?
- California DFPI
Last reviewed 2026-10-12. Sentinel Answer · San Jose, California.