This letter proves your Social Security or Supplemental Security Income (SSI) amounts for situations ranging from assisted housing and fuel assistance programs to mortgage applications. You can also verify the type of benefits received without showing amounts. You select the information to be shown. Depending on your needs, the letter can provide amounts of monthly Social Security and Supplemental Security Income (SSI), show the type of benefits received, if you have Medicare, or other information. The proof of income letter will arrive in about ten days. When requesting the letter, you will see a screen asking what information should be included. A letter showing all available benefit information is available, but including only the minimal information that you actually need is suggested for privacy reasons. Choices include one or more of the following. The amount of your most recent monthly Social Security benefit and when you began to receive that amount The amount of your prior monthly Social Security benefit and the dates you received it The amount of your current monthly Supplemental Security Income (SSI) payment and when you began to receive that amount The proof of income letter is mailed to your address as shown on Social Security records. If you recently moved, and have not yet reported your new address change, contact Social Security instead of using this online process. Request verification of your benefit, and update your address at the same time, by calling the national SSA toll-free number, 800-772-1213 (TTY 800-325-0778) or your local office.