If you have had the unfortunate experience of having cheques stolen from your mailbox or elsewhere you will not be able to accomplish much by notifying the credit bureaus about it. Since a cheque drawn on a checking or assumes a counter the bank is not reported to the credit bureau any fraudulent transaction that is carried on henceforth will not make a difference to your credit history or your credit score. However, he must immediately notify the police about the theft as well as your bank in order to prevent further fraudulent transactions happening on that current account. You must also consider closing that particular account completely. If it is only a cheques that the stolen then these measures should suffice but in case you suspect that other information could have also been stolen from a mailbox that could lead to an identity theft and subsequently credit fraud then you should notify the lenders whose account numbers you feel might have been compromised. If the fraudulent transaction is made on these accounts, you will probably noticed first in your account billing statements.
Depending upon the amount of information that was stolen that he could also try an open and new credit account in your name. Such enquiries will appear on your credit report.
If you suspect that you might be made a victim of a credit fraud based on the information that was stolen it will be a good idea to put in initial security alert on your credit report. The initial security alert were last will be that of 90 days and will alert all the lenders that you may be made a victim of credit fraud. In the presence of her fraud alert on credit report lenders are required by the federal law to take extra measures to verify that the duty of the applicant which includes contacting you in person and asking for additional documents to verify the identity.
Whenever you place fraud alert with anyone of the credit bureaus it is shared automatically with the remaining credit reporting agencies as will. For example, if you place a fraud alert with your credit report with Experian, transunion and Equifax will automatically be notified as well.