The validation notice and its window
Third-party collectors generally have to send a validation notice early in their contact with you, stating the amount, the creditor, and how to dispute. If you dispute in writing within the period that notice describes, the collector generally has to pause collection until it provides verification of the debt. A dispute raised later is still worth making; the federal pause may not apply, but New York rules let you ask a collector to substantiate a charged-off debt later in the process, and collection generally has to stop until it does. Original creditors collecting their own accounts are not usually covered by this validation process, though other consumer protections may still apply.
Making the dispute count on paper
Put the dispute in writing, keep a copy, and keep proof of when you sent it. Say what you dispute, whether it is the entire debt, the amount, or the claim that the account is yours, and ask for documents showing the original creditor and the balance history. Keep the collector's letters, envelopes, and any record of calls or texts. If you believe the account resulted from identity theft, a report to the Federal Trade Commission and, where appropriate, a police report support the dispute. Be careful about agreeing to pay or making a small payment before the account is reviewed; New York changed its rules so that a payment generally does not revive an expired consumer credit debt, but other states can treat this differently.
Credit reports, lawsuits, and next steps
A collection account on your credit report can be disputed separately with the credit bureaus, which then pass the dispute to the company that reported it. A dispute letter does not stop a lawsuit, and if you are served, the court's deadline controls regardless of where the dispute stands. In a first conversation we review the notices and your correspondence, check whether the collector's conduct followed the rules, and decide whether a further letter, a credit report dispute, or a different response fits. Sometimes the sensible outcome is a documented settlement of a balance you do owe. In other matters, a collector's violations give you claims of your own.