I have a charged off credit card account on my credit reports from 1997. The tradeline is listed by the credit card company but NCO is calling me to collect. I want to start the validation process. Do I send the letters to NCO or the creditor or both? If I receive no answer to the validation letters, do I send copies of the letters and postal receipts to the credit bureaus along with my request to delete the tradeline? Thank you for any info you can give.