Understanding Check Basics: The Essential Numbers and How to Use Them Correctly

While digital payments dominate today’s financial landscape, paper checks remain a staple in banking. Whether you’re paying rent, receiving a paycheck, or settling a vendor invoice, knowing the fundamentals of check writing and processing is essential. This guide breaks down everything from identifying key check components to properly endorsing one before deposit.

The Three Critical Numbers on Every Check

Before writing or depositing a check, you need to understand the three identification numbers printed on every check. These numbers serve different purposes in the banking system.

Routing Number (Nine Digits)

Every financial institution has a unique routing number that identifies which bank processes the check. This nine-digit code appears on the bottom left of your check and is crucial for any electronic banking transaction or wire transfer you might initiate. Banks use this number to route funds to the correct institution.

Account Number (Your Personal Identifier)

Located at the bottom center of the check, your account number identifies your specific checking account within the bank. This number ensures funds are deposited into the correct account and distinguishes your account from all others at the same institution.

Check Number (Sequential Tracking)

Each check in your checkbook carries a unique number that appears in two locations: the upper right corner and at the bottom left near the routing number. This sequential numbering helps you track which checks you’ve written and maintain an accurate record of your transactions.

Filling Out a Check: Step-By-Step Instructions

Writing a check correctly is straightforward, but precision matters. A single error can delay payment or create complications. Here’s what you need to do at each stage.

Step 1: Add the Date

In the upper right corner, write the date you’re issuing the check. While this is typically today’s date, some situations—such as paying a future bill—may require a future date. The date helps the recipient know when the check was written and when it should be deposited.

Step 2: Identify the Payee

On the line marked “Pay to the Order of,” write the exact name of the person, business, or organization receiving the payment. Accuracy is critical here. If you’re unsure of the correct spelling or legal name, verify it before writing the check. A mismatched name can cause the check to be rejected.

Step 3: Enter the Numerical Amount

In the box on the right side of the check, write the payment amount in numbers (for example, $87.50). Position this amount as far left as possible within the box to prevent fraud. If you leave space on the right, someone could potentially add digits and alter the amount.

Step 4: Write Out the Amount in Words

Below the payee line, spell out the exact dollar amount. For a check of $87.50, you’d write “Eighty-seven dollars and 50/100.” If the written amount and numerical amount don’t match, banks legally defer to the written version, making this step critical.

Step 5: Use the Memo Line (Optional but Helpful)

The memo section allows you to note the check’s purpose. Writing “Rent Payment—January” or “Invoice #2024-156” helps you track payments later. This is especially useful for tax deductions, utility payments, or vendor invoices where you need a paper trail.

Step 6: Sign the Check

Sign your name on the line in the lower right corner. Your signature authorizes the payment and confirms your identity. A check is invalid without a proper signature—this is a legal requirement, not optional.

Real-World Example: Writing a Check for Rent

Let’s walk through a practical scenario. Suppose you’re mailing a rent check to your landlord for $1,250.

• Date: Write today’s date (for example, January 15, 2025)
• Payee: Write your landlord’s name or property management company name exactly as specified in your lease
• Numerical amount: Write “$1,250.00” in the box
• Written amount: Write “One thousand two hundred fifty dollars and 00/100”
• Memo: Write “Rent—January 2025” or your unit number
• Signature: Sign after double-checking all information

Best Practices for Check Writing and Record-Keeping

Maintaining good check-writing habits protects your account and finances.

Track Every Check You Write

Keep a check register (whether paper or digital) recording:

• The check number
• The date written
• The payee name
• The transaction description
• The amount

This record helps you monitor spending, spot unauthorized transactions, and reconcile your bank statement each month.

Reconcile Monthly Statements

Balancing your checkbook involves matching your records against your bank’s statement. This catches errors early and gives you a clear picture of your financial position. It’s easier to dispute an unauthorized check soon after it appears than months later.

Protect Against Check Fraud

Use these precautions when writing checks:

• Write with pen so information cannot be erased
• Never sign a blank check
• Fill in the payee and amount before signing
• Avoid writing checks “to cash”
• Don’t leave blank space on the amount line
• Keep blank checks secure

Do You Need to Sign the Back of a Check? Understanding Check Endorsements

When you receive a check, you must endorse it—meaning you need to sign the back of the check—before depositing or cashing it. This endorsement serves as proof that you’re the intended recipient and authorizes the transaction. The signature on the back must match the payee name on the front.

If your name is misspelled on the front, sign it with the incorrect spelling first, then sign it correctly below. This protects you if there’s a discrepancy the bank needs to resolve.

Blank Endorsement

The simplest method is signing your name on the back with no additional instructions. You’ll then tell the bank teller whether you want the check cashed or deposited. While convenient, this is the least secure option—anyone holding the check could potentially cash it.

Secure Endorsement (“For Deposit Only”)

To add security, write “For Deposit Only to Account Number [Your Account Number]” and then sign below. This restricts how the check can be used. Wait until you’re ready to deposit the check before adding this endorsement for maximum protection.

Third-Party Endorsement

If someone gives you a check and you want to pass it to another person, you can write “Pay to the Order of [Person’s Name]” and sign it. However, not all banks accept third-party endorsements, so confirm with your bank first.

Business and Multiple-Payee Endorsements

Checks written to a business require an authorized representative’s signature along with their job title. For checks made out to multiple people using “and” (like “John and Jane Doe”), both must sign. If it says “or,” either party can endorse it.

Mobile Deposit Endorsement

Some banks require specific language for mobile deposits, such as “For Mobile Deposit to [Bank Name].” Check your bank’s app or contact customer service for their requirements before endorsing.

Depositing a Check: Your Options

Once you’ve properly endorsed a check, you have multiple deposit methods.

In-Person Branch Deposit

Visit your bank with your endorsed check and valid ID. Present it to a teller, complete a deposit slip if required, and specify whether you want the funds credited to checking or savings.

ATM Deposit

Many banks offer ATM check deposits. Endorse your check, insert your debit card, follow the on-screen prompts, and place the check in the designated slot (or envelope if provided). Confirm the deposit amount matches the check.

Mobile Check Deposit

Using your bank’s app, select the deposit account, enter the check amount, and photograph both the front and back of the endorsed check. Keep the original check until the funds appear in your account, then destroy it.

Ordering New Checks

When you run out of checks, reordering is simple. Many banks provide complimentary checks with new accounts; otherwise, you’ll pay for them.

Order Through Your Bank

Log into your online banking account and look for the “Order Checks” option under account services. You can typically select check designs and quantities. Have your current check handy for the routing number, account number, and other required information.

Third-Party Providers

Companies outside your bank also sell checks, sometimes at lower prices. You’ll need to provide your bank name, account number, routing number, and desired starting check number.

Note the check number of your last check so new orders start with the next sequential number.

Common Questions About Checks

Can You Write a Check to Yourself?

Yes. Writing a check payable to yourself lets you withdraw cash or transfer money between your own accounts. Simply write your name on the payee line, endorse and deposit it as usual.

Are Post-Dated Checks Legal?

In most cases, yes. A post-dated check has a future date and may be written when payment isn’t due yet or funds aren’t currently available. Check your state’s specific laws for regulations.

What About Writing a Check to the IRS?

Make the check payable to “U.S. Treasury” (not the IRS). Include your name, address, phone number, Social Security number or EIN, tax year, and the relevant tax form or notice number. Refer to the IRS website or a tax professional for the correct mailing address.

Can Checks Be Deposited at ATMs?

Many banks allow ATM check deposits. Contact your institution to confirm they offer this service and to learn their specific procedures and deposit limits.

Conclusion

Check writing remains relevant despite the rise of digital payments. Mastering the basics—from identifying the three key numbers to properly endorsing and depositing checks—ensures smooth financial transactions and protects you from fraud. Whether you’re writing rent checks, business payments, or depositing personal checks, following these guidelines keeps your banking efficient and secure.