man at ATM

PIN Numbers: What They Are And Why They Matter

Cathie Ericson5-Minute Read
July 20, 2021

PIN numbers are everywhere – you use them to log into your bank account, your devices, and just about every account you have. Even though you might feel like your entire financial existence has been reduced to a few digits, you’ve probably never stopped to think about why they are so important. Let’s find out more about what PIN numbers are and why they matter. 

What Is A Personal Identification Number (PIN)?

A personal identification number (PIN) is a series of numerical digits that help safeguard your financial accounts. It is typically used in conjunction with taking money out of your bank or credit union account  at the ATM or completing a transaction with your debit card or credit card at the point of sale (POS) system at a store. It adds a layer of security to electronic transactions so that someone who has your physical card can’t empty your bank account or run up charges.

While PIN numbers are primarily used in financial transactions, they also are used for authentication purposes on your computer, mobile phone, and home security system, to name just a few additional applications. It’s usually a four- or six-digit string, although some may be longer for even more security.

How Are PIN Numbers Chosen?

When you open a new bank account or get a new debit card or credit card, your financial institution might assign you a four- or six-digit PIN number that you can then charge to something that’s easier for you to remember – but not so easy that it’s simple for a nefarious individual to guess or use in identity theft scams; you’ll find more details for what to keep in mind when creating one as you keep reading. If you aren’t assigned a PIN number, the card issuer will typically ask you to input one of your own choosing into the system.

What Is My PIN Number?

If you’re forgetting your PIN number, don’t despair. Your bank will ask you a series of identifying questions and/or request documents in order to set up a PIN, reset it, or change it to something more memorable. Just remember that you should never change your PIN number because someone contacts you and asks you to; only share that information if you have initiated the transaction and you feel confident that the bank has asked for an appropriate amount of evidence to adequately verify it’s you.

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Why Are Personal Identification Numbers Important?

A PIN number is a crucial way to keep your information safe. It offers identity authentication, which reduces the risk of identity theft through your bank; provides added security to your bank account in case your card is misplaced or stolen; and also adds security for online or in-person merchants so they can’t be scammed out of goods or services with a stolen card number that you, as the rightful owner, later dispute.

Because it serves as the last line of defense to your finances, you’ll want to take the protection of your own very seriously.

Tips For Creating A Secure PIN Number

If your card issuer or bank or credit union didn’t assign you a PIN number or you want to reset it to something that’s easier for you to remember, you’ll want to carefully think through the digits you choose. You want to create something that’s not too easy to guess should someone get hold of your card. In general, the longer the PIN, the better, if you are allowed to set one of any length. But if the PIN is prescribed at four or six digits, you’ll want to be extra careful not to use information that’s too easy for someone to identify.

Here are some tips on what to avoid when creating a secure PIN number.

Don’t Use Segments Of Your Social Security Number

While you shouldn’t carry your Social Security card with you, the number is also sometimes used for other identification purposes, such as for medical information. Any number that is easily associated with you is easier to guess and shouldn’t be used as a PIN.

Don’t Use Segments Of Your Home Address Or Phone Number

The same principle is at work here – someone can relatively easily deduce your home address or phone number and guess that it’s also potentially your PIN number.

Don’t Use Significant Dates From Your Personal Life

You always remember your anniversary, don’t you? That might make it seem like a wise number to use … ditto your mom’s or child’s birthday or any other date that’s on the tip of your tongue.

Unfortunately, those numbers are also easy for someone to guess if they know you well or even if they just do a little digging into your social media accounts.

Don’t Use An Obvious Numerical String

1-2-3-4 … No. 1-1-1-1. No. Not even 4-3-2-1. Believe it or not, 2580 is another common one … and a no-no. (Can’t guess why? It’s the vertical column on a numeric keypad.) The principle here is simple: Avoid using a PIN like this that can be guessed in a minute by an intrepid hacker.

Don’t Use the Same Number for Everything

Once you’ve devised a fantastic PIN number, it’s tempting to want to use it on multiple accounts. After all, if you’ve remembered it once, you’ll remember it every time. Unfortunately that’s common practice which means that if you lost your entire wallet, all of your accounts could be vulnerable to someone who figures out one PIN and then proceeds to use it with all your other cards, devices, etc. Use a different PIN number for every account to be on the safe side.

How To Protect Your PIN Number

Wondering how to keep your PIN number safe? The most important thing you should do is avoid ever writing it down where someone can easily find it, such as in your wallet or car or (even worse) affixed to the front or back of your debit card or credit card. You also shouldn’t keep it in your desk at work, just in case someone goes through your drawers after hours.

And of course don’t ever share your PIN number with anyone.

Finally, be careful when you’re keying it in at a POS system at a store or gas station or at your bank’s ATM. You don’t want to inadvertently reveal the number to someone who’s looking over your shoulder. Be aware of who’s around and use your hand to cover up the keypad if you believe you are being watched. (Better yet, alert a store or bank employee in order to safeguard not just you, but others, as well.)

If you feel your PIN number might have been compromised, it’s best to contact your bank or credit union and find out how to change it for your peace of mind.

The Bottom Line: Keep Your PIN And Personal Finances Safe

While it might sometimes feel like a pain to use a PIN number, it’s an important piece of your financial security to ensure that someone doesn’t access your account or steal your identity. Creating a password that’s meaningful to you – but no one else – is the best way to ensure those important digits are at the front of your mind when you need them but aren’t easy for others to deduce.

Wondering how else to safeguard virtual transactions? Chances are good that you’ve blended other payment methods into your repertoire. Check out the Rocket HQSM article on the differences between Venmo and PayPal to make sure you choose the channel that’s right for each transaction.

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Cathie Ericson

Cathie Ericson writes about personal finance, real estate, small business, education, retail/ecommerce and other topics for a host of brands and websites. Her work has been featured on major media websites, including U.S. News & World Report, Forbes, Business Insider, The Oregonian, Industry Dive, Boston Globe, CNBC,, and Yahoo Finance, among many others. Find her