Identity Theft Personal Finance

Who Really Needs Your Social Security Number?

Written by Eric Rosenberg

Your Social Security number is a valuable asset used for everything from filing your taxes to opening new credit cards. Until recently, most American’s Social Security numbers were secret, but thanks to Equifax, America’s Social Security numbers are effectively open source. But while our information may have been leaked, we should still take steps to be smart and protect ourselves from identity theft.

One method to thwart identity thieves is to be as judicious as possible when giving out your Social Security number. While you may be asked for it from time to time, it’s important to understand when to say yes and when to say no. Read on to learn about who actually needs your social security number and why.

Where to give out your Social Security number

Some businesses and organizations legitimately need your Social Security number, while others simply prefer to have it to make their life a little easier. When these businesses and organizations need your Social, it’s okay to say yes.

Internal Revenue Service

They say there are two guarantees in life: death and taxes. For the latter of the two, you need to use your Social Security number. Every time you file taxes or any other form with the IRS, you’ll need your Social Security number. As the IRS is part of the government and your Social Security number is a government ID number, this link makes a lot of sense.

If you have any self-employment income, you may want to register for a free Employer ID Number, or EIN, from the IRS so you don’t need to use your personal government ID number for business purposes. But when you do your taxes or file other tax forms, you can expect to need your Social Security number handy.

Banks and lenders

Banks are required to follow strict guidelines on who they open accounts for and do business with, and they use your Social Security number to uniquely identify you. A bank may also use your Social to report interest income to the IRS.

When applying for new credit, expect to hand over your Social too. Lenders use your Social Security number to lookup your credit score and credit report, which is the primary factor in deciding who is approved and who is denied for a new loan or credit card.

Cash transactions over $10,000

When you partake in any cash transaction over $10,000, the government tracks it to prevent money laundering. Even if you are doing things on the up-and-up, you’ll need to hand over your Social for these large cash transactions.

When you partake in one of the large transactions in cash, a Currency Transaction Report, affectionately called a CTR, is required. The CTR came into force in 1986 with the Money Laundering Control Act, and requires a Social Security number. If banks find other cash transactions suspicious, even if below the $10,000 threshold, they may choose to file a Suspicious Activity Report (SAR) regardless.

Your employer

When you get a new job, your new employer should require you to complete two forms: IRS form W-9 and Homeland Security form I-9. The W-4 determines your income tax withholding, while the I-9 verifies that you are legal to work in the United States.

For a W-9, you need to enter your Social Security number, which your employer continues to use for wage and tax reporting. The I-9 allows you to use one of a list of documents, including your Social Security card. If you want to skip your Social on this card, you can use your United States birth certificate or a few rare forms of ID.

Department of Motor Vehicles

If you want a driver’s license, the DMV wants to make sure you are who you say you are. To do so, they typically require a Social Security number. Pretty much everyone needs a driver’s license or government ID, so most American adults can’t avoid this one.

In reality, they are the government and already know pretty much everything about you, so there shouldn’t be a reason to be skeptical of the DMV’s need for your Social Security number.

Where to keep your Social Security number private

Some businesses and organizations may ask for your Social Security number, but notate the box as optional. When that’s the case, leave it blank! In other cases, you may be able to use an alternate ID number. Here are some places that you should not be required to hand over your Social Security number, but that doesn’t mean they won’t ask.

Hospitals and doctors

Insurance companies, hospitals, and doctors’ offices like to use Social Security numbers as an identifier because only one person in the country has a given Social Security number. But in this case, you shouldn’t have to hand over your Social.

You may need your Social Security number for some insurance tax reporting related to the Affordable Care Act, but otherwise there is no technical need for anyone in the medical profession to use your Social.


Schools are another gray area, as they are part of the government. But there is a Federal law that requires you do not have to provide that number to your kid’s school or your school, whether it’s a K-12 public school, private school, university, or college.

School districts typically do request Social Security numbers on registration forms, but the Privacy Act of 1974 says that you can leave that box blank. If the school doesn’t like it, they can take it up with Congress.


Similar to hospitals and doctors, pharmacies may ask for your Social Security number when you first go in for a prescription or when you update your insurance information. Like with hospitals and doctors, you can say no.

Offering your Social here may save time at the counter while the pharmacist matches your information to the insurance database, but they can look you up other ways, like with your insurance number on your insurance card.


Airlines have a big job to do when it comes to security, so some occasionally ask for your Social Security number. You don’t have to hand it over by any means. You do probably need to provide a government ID, however, and a valid passport number for international travel.

If you are signed up for Global Entry or TSA PreCheck, you definitely want to provide your trusted traveler ID number to the airlines, as that helps ensure you get the PreCheck mark on your boarding pass to skip the long security line.

Bonus tip: never give out your Social Security number on the phone if you were not expecting a call

One bonus tip, if someone that you were not expecting calls and asks for any personally identifying information, don’t give it to them. Thanks to social engineering, a phone version of online Phishing, a caller may pose as a banker or government worker in a ploy to get your information.

If you call a bank and they ask, it’s okay to give out your Social because YOU called THEM. But if you get an incoming call, you can’t always identify that the caller is who they say they are. If that’s the case, err on the side of caution and keep your information to yourself.

About the author

Eric Rosenberg

Eric Rosenberg is a finance, travel, and technology writer originally from Denver, Colorado living in Ventura, California. When away from the keyboard, Eric he enjoys exploring the world, flying small airplanes, discovering new craft beers, and spending time with his wife and baby girl. You can connect with him at his own finance blog Personal Profitability.

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