20 CFR § 408.340 - When will we use a written statement as your filing date?
If you file with us under the rules stated in § 408.325 a written statement, such as a letter, indicating your intent to claim SVB, we will use the filing date of the written statement as the filing date of your application. If the written statement is mailed, we will use the date the statement was mailed to us as shown by the United States postmark. If the postmark is unreadable or there is no United States postmark, we will use the date the statement is signed (if dated) or 5 days before the day we receive the written statement, whichever date is later, as the filing date. In order for us to use your written statement to protect your filing date, the following requirements must be met:
(a) The statement indicates your intent to file for benefits.
(b) The statement is signed by you, your spouse, or a person described in § 408.315.
(c) You file an application with us on an application form as described in § 408.310(a), or one is filed for you by a person described in § 408.315, within 60 days after the date of a notice we will send advising of the need to file an application. The notice will say that we will make an initial determination of your qualification if an application form is filed within 60 days after the date of the notice. We will send the notice to you. However, if it is clear from the information we receive that you are mentally incompetent, we will send the notice to the person who submitted the written statement.
(d) You are alive when the application is filed.