It is important you report any incidences of id theft to the necessary authorities, not only to protect your own financial accounts and good name, but also so that any further action that needs to be taken by various authorities is carried out. Those organizations and departments you need to inform include:
Federal Trade Commission (FTC) - the FTC have a dedicated, toll-free identity theft hotline on 1-877-ID THEFT (877-438-4338), and are the department responsible for receiving complaints from anyone who believes they may have been a victim of identity theft crimes. The FTC provide help and support for identity theft victims, and there is a lot of information on this issue at their website ftc.com
Law Enforcement Agencies - the police, FBI and US Secret Service are all involved in tackling identity theft crime, so if you do become a victim you should report the details to a local branch of these services.
US Postal Service (USPS) - if you are concerned that your mail has been tampered or even redirected without your knowledge, then you should report this to the US Postal Inspections Service immediately.
Social Security Administration (SSA) - you should report any suspicion of Social Security Number fraud immediately to the SSA on the dedicated fraud hotline 800-269-027.
Internal Revenue Service (IRS) - if you suspect your identity has been used in conjunction with tax evasion or any other tax violations then you should contact the IRS as soon as possible on the dedicated fraud hotline 1-800-829-0433.
Credit Agencies - you should report cases of identity theft to the main credit agencies, which will be able to take further action to protect consumer credit reports of those involved and investigate any fraudulent activity. To report identity theft to Equifax call (800) 525-6285, to Experian call (888) 397-3742 and to TransUnion call (800) 680-7289.
Creditors and Financial Institutions- if you have any existing credit accounts such as loans, service agreements, bank accounts etc, then you will need to contact the providers as soon as possible if you suspect they may be vulnerable due to identity theft. This can prevent any fraudulent charges and debts from being run up on your accounts.