Routing and Account Numbers: What You Need to Know

Search Fintrev

Search our guides, reviews and glossary.

Routing and account numbers are the two strings of digits that let a payment find your money. The routing number identifies your bank or credit union. The account number identifies your specific account at that institution. On a standard personal check, both are printed along the bottom edge: the nine-digit routing number comes first on the left, the account number follows, and the check number usually comes last.

Routing number vs. account number at a glance

The two numbers do different jobs and are not interchangeable. A routing number alone cannot move money, because it only points to the bank. An account number alone is useless to the payment system, because the system would not know which bank holds it. Every electronic funds transfer through a U.S. bank needs both.

Reading the bottom of a check

The numbers along the bottom of a check sit on the MICR line (Magnetic Ink Character Recognition, pronounced “micker”). The digits are printed in magnetic ink with a special font so bank processing equipment can read them automatically.

On a typical personal check you will see three groups:

1. Routing number: nine digits on the far left, usually set between two small symbols that look like a vertical bar with two squares (the transit symbol).
2. Account number: the next group, followed by a symbol that looks like a vertical bar with three short lines (the “on-us” symbol).
3. Check number: the last group, which matches the number printed in the upper right corner of the check.

If you are unsure which group is which, count digits. The group with exactly nine digits between transit symbols is the routing number. The check number is the short group that matches the number at the top of the check. What remains is your account number.

Some checks, especially business checks, put the check number on the left before the routing number. Cashier’s checks and other bank-issued checks may arrange the numbers differently and show the bank’s own account rather than yours, so take your numbers from your personal checks or your bank’s records.

You may also notice a small number written like a fraction in the upper right area of a check, near the check number. This is the older routing symbol (fractional routing number), a few digits that also identify the bank. It predates the MICR system and is rarely used in processing today. Don’t enter it in a form asking for a routing number.

An example

Suppose the bottom of a hypothetical check reads:

⑆123456780⑆ 000987654321⑈ 1052

• 123456780 is the routing number (nine digits between transit symbols).
• 000987654321 is the account number.
• 1052 is the check number.

What the routing number tells you

The routing number system was created by the American Bankers Association in 1910, which is why it is called an ABA routing number or routing transit number. A valid routing number indicates the institution is federally or state chartered and holds an account with the Federal Reserve.

The nine digits have a structure:

• First four digits: the Federal Reserve routing symbol. The first two of these tie the number to one of the 12 Federal Reserve districts (01 to 12 for banks, with other ranges such as 21 to 32 used for thrift institutions).
• Next four digits: the ABA institution identifier.
• Ninth digit: a check digit, calculated from the first eight.

The check digit catches typing errors. Multiply the digits in positions 1, 4 and 7 by 3, the digits in positions 2, 5 and 8 by 7, and the digits in positions 3, 6 and 9 by 1. If the total is evenly divisible by 10, the number passes.

Using the hypothetical 123456780:

• 3 × (1 + 4 + 7) = 36
• 7 × (2 + 5 + 8) = 105
• 1 × (3 + 6 + 0) = 9
• Total = 150, which divides evenly by 10.

Passing this test only shows the number is correctly formed, so always take the routing number from your bank directly.

Is the routing number the same for everyone at a bank?

Each routing number belongs to one institution, but an institution can have more than one. Small banks and credit unions often have a single routing number used by every customer. Large banks may assign routing numbers by the state or region where the account was opened, so two customers of the same bank in different states can have different routing numbers.

Mergers add another layer. When banks combine, the surviving bank may keep older routing numbers active for accounts from the acquired bank. A routing number lookup may therefore show a name or address that differs from your branch, because it reflects the institution’s records. If the name doesn’t match your bank at all, confirm with your bank before using it.

Historically, some banks used one routing number for paper checks and another for ACH transactions. Most banks now use one routing number for all transactions.

Domestic, ACH and wire routing numbers

The routing number on your checks is the one used for most domestic activity: direct deposit, ACH debits and credits, and bill payments. Some banks, however, publish a separate routing number for wire transfers. When a form or bank website distinguishes a “domestic” or “ACH routing number” from a “wire routing number,” use the one that matches the payment type. Using the check routing number for an incoming wire at such a bank can delay or reject the transfer. ACH transfers and wire transfers also differ in speed, cost and whether a payment can be reversed.

For money coming from outside the United States, the sender’s bank typically needs your bank’s SWIFT/BIC code plus your account number, and sometimes intermediary bank details. Your bank’s website or customer service will list its international wire instructions. Don’t assume the routing number on your checks will work.

Many other countries, including those across Europe, use an IBAN (International Bank Account Number), up to 34 alphanumeric characters encoding the country, bank, branch and account in one string. U.S. accounts have no IBAN. When you send money to an IBAN country, you provide the recipient’s IBAN instead of a routing number.

Account numbers

Your account number is assigned when you open the account and tells the payment system exactly which account to debit or credit. Most U.S. bank account numbers run roughly 8 to 12 digits, though some are longer. The ACH format allows up to 17 characters.

Each account has its own number. If you have a checking and a savings account at the same bank, they will usually share a routing number but have different account numbers. Your savings account number won’t appear on your checks, so find it in online banking or on a savings statement.

Your account number is also different from your debit card number. Debit and credit cards run on card networks and are identified by the card number, expiration date and security code, while a routing number belongs to a bank account. Giving a card number where a form asks for bank account details will fail.

Where to find your numbers without a check

• Online banking or the mobile app: account details screens usually show the routing number and the full account number, often after a tap or extra verification.
• Bank statements: the account number appears on statements, sometimes partially masked.
• Direct deposit forms: many banks generate a prefilled form with both numbers in their app.
• Your bank’s website: banks list their public routing numbers online, often by state. Make sure you’re on the bank’s own site.
• Phone or branch: your bank can give you both numbers after verifying your identity.

When you need both numbers

• Setting up direct deposit for a paycheck or Social Security benefits
• Paying bills electronically from your bank account
• Linking a bank account to a payment app such as PayPal or a digital wallet
• Paying federal taxes to the IRS or receiving a refund by direct deposit, or paying state and local taxes
• Reordering checks
• Moving money between accounts at different banks

Most forms also ask for the account holder name (the name on the account exactly as the bank has it) and the account type (checking or savings). Choosing the wrong type with the right numbers can still cause a rejected payment.

Keeping your account number safe

Because a routing number is public, the account number is the part worth protecting. With both, someone could attempt unauthorized ACH debits or create fraudulent checks. Share them only with employers, billers and services you’ve verified, and only through their official channels.

Review statements regularly. Under federal rules, how quickly you report an unauthorized electronic transfer can affect how much of the loss you’re liable for.

Before submitting any payment, double-check both numbers digit by digit. A typo in the routing number usually causes a rejection. A typo in the account number can be worse if it happens to match another valid account.

The Bottom Line

Anyone setting up direct deposit, paying bills or taxes electronically, or linking a payment app needs both numbers and the correct account type. Take the routing number from your bank or your own checks rather than a lookup, and use the wire or SWIFT details when the payment calls for them. Guard the account number, check every digit before submitting, and review statements so you can report unauthorized transfers quickly.