Many initial bankruptcy notices will have an attached proof of claim form. (Click here to obtain a standard B10-proof-of-claim form.) Most general unsecured creditors will have an "unsecured nonpriority claim". The claim form should be self-explanatory. Fill in the appropriate blanks and attach sufficient documentation to support your claim, such as a statement, invoices, application, personal guarantee, etc. Make a copy of the executed proof of claim form and mail it to the bankruptcy court (the address will be on the notice), along with a self-addressed, postage paid envelope. Ask the court to time-stamp the copy of your proof of claim and send the time-stamped copy back to you in the postage paid envelope. This serves as proof that your claim was received and filed. In cases where you have retained CST Company to file suit and obtain judgment, it may be a good idea to file a proof of claim through CST Company. The judgment will often serve as a lien on real estate and this can come up at various times during the bankruptcy proceedings. By having the claim filed through CST Company, or the local attorney CST Company obtained for you, your interests can be protected if such a situation develops, and CST Company or the attorney can immediately act in your behalf.