In places like pharmacies, an assistant may ask you for your social security number in order to open up the computer record of your visit. Always decline when asked to provide your social security number. You may ask the person if it is okay to use the last four digits of the social security number. If they insist, you may write it down for them, or tell it to them, as long as there are no others standing nearby. Legitimate companies that you do business with will never call you requesting any personal information of any kind. So if you receive any phone calls from a representative of a company requesting your social security or other personal identification numbers, hang up immediately. If you must give out a number to access an account like a bank, or credit card for security purposes, always ask if you can just use the last four digits of your social security number.