1. Anyone who calls or sends you an official-looking email, who texts you a link to any site or designates a number to call where you are asked to confirm your SSN. If they call, check the credit or debit card that is the subject of the communication, call the customer service number listed on the back, and ask for the security department. If they email or text, do the same, or go directly to the institution's website (provided you know who they are). Make sure you type the correct URL, and make sure that the page where you are asked to enter your information is secure. Only provide personal information if you're the one who controls the interaction.
2. Public schools: Your utility bill confirms your address. Your email and phone number give them channels to contact you in an emergency. Asking for your Social Security number is overkill.
3. Little League, summer camp and the like: For the same reasons as school, a Social Security number should never be required by these groups. If they ask for your child's birth certificate, show it to them, don't leave it with them unless they can prove they will protect it. And even then, can you really believe them? If you use credit to pay for the activity, the organization may need your Social Security number. If you pay for it upfront or with a direct debit to your bank account or credit card, they don't. Period.
4. Supermarkets: A frequent shopper card is neither a loan, nor a bank account. It's merely a tool grocery stores use to track your purchases, primarily for marketing purposes. Regardless, many supermarket chains request customers' Social Security numbers on their application forms. Refuse.
5. Anybody who approaches you on the street, whether it's a cell phone company salesman offering a free T-shirt or someone running a voter registration campaign: Never, ever give your SSN. If you want an ill-fitting T-shirt festooned with corporate logos, buy one. If you want to register to vote, go to your county board of elections in person.
This is the short list. There are plenty of other organizations that should never get your Social Security number, and if you know one that I've left out, please leave it in the comments.
Don't just hand it over
Once you realize how often you are asked for your Social Security number, you may be surprised. It happens literally all the time. So, the next time someone does, as they inevitably will, here's how to handle it:
1. Take a minute and think. Maybe they ask for SSNs blindly, because everyone else does, or because that's how they've always done it. Maybe they actually need it. See if their reason sounds legitimate. (For example, Credit.com's Credit Report Card does ask for your SSN in order to generate your credit score and credit report summary -- an industry standard -- but the information is fully encrypted with a bank-level authentication process.)
2. Negotiate. There are many different ways to identify you without a Social Security number, including your driver's license or account number. Fight to use those instead.
3. If you must share your Social Security number, do so, but make sure the people taking it down have strong security measures in place to protect it. That said, you only have their assurance and frankly, in light of the mistakes people make and the sophistication level of hackers, who really knows if they can protect it?