Your Social Security Number (SSN) is a nine-digit identification number you are assigned by the United States government. It is necessary to have one if you want to apply for a job, secure a bank loan or create an account with many utilities. Due to this importance, you should protect your SSN as best you can. One way to protect it when you're composing a document is to replace the numbers with Xs.
Divide nine Xs into three sections: three-two-four. This mimics the format of an SSN.
Separate the sections with dashes. For example, XXX-XX-XXXX.
Replace the Xs with any numbers of your SSN. A common security check with most companies is to ask you for the last four digits of your SSN, so you can write out XXX-XX-5555.