The federal Fair Debt Collection Practices Act gives you the right to request that a debt be validated. However, you must make the request within 30 days of receiving the initial collection notice from a debt collector.
Put your request in writing and send it to the debt collector via certified mail, with a return receipt requested. If you request validation by phone, follow up in writing and again, send your letter via certified mail and ask for a return receipt.
Make a copy of your letter before you mail it. Keep it and the return receipt in your files as proof that you requested verification. You may need that proof later.
The debt collector is legally obligated to respond to your request in writing. If he does not, he has violated the law and you should get in touch with a consumer law attorney who helps consumers resolve debt collection matters.
Validation not required in 1st 30 days by: Anonymous
You state that debt validation letters have to be submitted in the 1st 30 days after notification of the debt. That is not true. In order to forestall collection efforts on the creditor's behalf, the validation request has to take place in that 30 days. However, a debtor can submit a validation request at any time, and the creditor is required to respond to it. If the debtor fails to request validation in the 1st 30 days, the creditor can continue collection efforts, but still must respond to the validation request.