Have you received a letter from a debt collector saying you owe money on a debt that you do not agree you owe? If so, do not ignore this letter. A letter from a debt collector will say you have thirty days to respond to the letter and if you do not, then the debt as stated in the letter will be considered as true and owing. So, within that thirty days, send the debt collector a debt validation letter. Below is a sample debt validation letter. Also, be sure to send the letter certified (green card) and keep a copy for your records.