After you've sent a dispute letter and waited your 30 days how do you know if anything changed? Do they tell you? Do they send you a corrected report or do you have to buy another one?
I assume you mean sending a dispute to the Credit Reporting Agencies: they will send you an "Investigation Results" document after the completion of the investigation. They will also send you an updated copy of your credit report. Please be aware of the time involved, the CRAs have thirty days from the time they receive the dispute. So, give up to five days for mail time. Then there may be up to five more days for mailing of your results. 40-45 days to get results back is not uncommon. If the dispute is a result from disputing a tradeline on a free report from www.annualreport.com, be aware that the CRAs have 45 days to conduct their investigation, and add the above mailing times. The CRAs can also take up to 45 days to investigate of you supply "additional information" during the investigation. Be patient, you have to give disputes some extra time beyond the 30 day window. Usually it is a good sign if it is stretching out to, or beyond, the 30 day window. This usually means the data furnisher has not responded, or "verified", the account as reported.