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Where is the routing number on a check?

Bottom left, nine digits, in magnetic ink — and then four things the check does not tell you, including why your wire routing number may be a different number entirely.

Glide Research14 min read
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In short

Where is the routing number on a check?

Your routing number is the first nine-digit block at the bottom left of a check, printed in magnetic ink; the account number sits to its right, and the check number to the right of that. The order is not universal — the IRS warns the two may appear in different places on your check.

Nine digits · first two are 01–12 or 21–32 · IRS Form 8888, Rev. 12-2025

What each number at the bottom of a check is

Federal Reserve Regulation CC defines a routing number as “the number printed on the face of a check in fractional form or in nine-digit form” — so a check can carry two of them, and only one is what a payer wants. The nine-digit form is the one in the code line along the bottom. Wells Fargo states the layout plainly: your account number “is located along the bottom of your check, to the right of the routing number and to the left of the check number.”

The code line on the IRS’s own sample check, read left to right
PositionWhat it isOn the IRS sample
First block, far leftRouting number — always nine digits250250025
Middle blockAccount number — length is set by your bank20202086
Last block, far rightCheck number — repeats the number in the top-right corner1234

Fields as printed on the sample check in IRS Form 8888 (Rev. 12-2025), page 2. The form’s own note under the diagram: “The routing and account numbers may be in different places on your check.”

The second routing number is the fraction in the top-right corner, under the check number — printed as 15-0000/0000 on the IRS sample. Regulation CC counts it as a routing number too, which is why it is there at all. But every form that asks for nine digits wants the block at the bottom, so the fraction is a curiosity rather than something to copy.

How to read the nine digits

The first two digits give the number away. IRS Form 8888 states the rule flatly: “The routing number must be nine digits. The first two digits must be 01 through 12 or 21 through 32.” 01 to 12 are the twelve Federal Reserve districts. The 21–32 band is the Fed’s parallel range for thrifts and credit unions — a leading 2 in districts 1 to 9, a leading 3 in districts 10 to 12.

The check-digit test, run on Chase’s wire routing number 021000021
DigitWeightProduct
030
2714
111
030
070
010
030
2714
111
Total30

30 divides by 10, so the number is well-formed. 021000021 is the routing number Chase publishes for domestic wires into a Chase account. This is the same test Glide’s routing-number lookup runs — isValidRoutingChecksum() in src/lib/ach-routing/index.ts.

The check-digit test is not a formality. Every routing number in the Federal Reserve ACH directory extract behind this site passes it — 18,198 out of 18,198, across 10,548 institutions. So a nine-digit number that fails the arithmetic is a transcription error, not an obscure bank you have never heard of.

Routing numbers in the directoryAll 18,198 pass the check-digit test
18,198
Institutions holding themBank of America alone files 148
10,548
Two-digit prefixes actually in use01–12, 21–32, and one outlier
25

Computed over apps/web/data/ach/routing-index.json — the FedACH directory extract (moov-io/fed) behind Glide’s routing-number pages, generated 2 August 2026.

There is exactly one exception in the whole file. Routing number 655060042 belongs to the Social Security Administration in Baltimore, Maryland — a federal agency rather than a depository institution, and the only entry whose first two digits fall outside 01–12 and 21–32. If you are checking a number against the prefix rule, that is the shape of the thing the rule does not cover.

Routing number vs account number vs SWIFT code vs IBAN

Four identifiers people mix up

They are not interchangeable, and three of the four never appear on a US check at all.

Four identifiers people mix up
FeatureRouting numberABA, United StatesAccount numberSet by your bankSWIFT / BICISO 9362IBANISO 13616
Length9 digitsVaries by bank8 or 11 charactersFixed per country — 22 in Germany, 27 in France
Printed on a US checkYesYesNoNo
What it identifiesThe paying bankYour account at that bankA business party and its countryOne account, country prefix included
Has a built-in check digitRouting numbers use a 3-7-1 weighted sum; IBANs use ISO 13616’s mod-97 testYes—NoYes
Issued in the United StatesThere is no United States entry in the ISO 13616 country table behind Glide’s IBAN checkerYesYesYesNo

Structure and lengths: ISO/TC 68 on ISO 9362 (BIC); Chase on SWIFT codes versus routing numbers; IBAN country lengths from the ISO 13616 table in Glide’s /tools/iban-checker. Checked 8 August 2026.

The practical version: a payer inside the United States needs your routing number and your account number. A payer outside it needs a SWIFT/BIC code plus your account number — Chase’s is CHASUS33, Wells Fargo’s is WFBIUS6S. Chase is blunt about the boundary: “Routing numbers are only used for transactions within the U.S. For any international transfer, a SWIFT code is typically used instead.” And nobody will ever ask a US bank for an IBAN, because no United States format exists in ISO 13616.

Wire and ACH routing numbers are not always the same number

This is the part that costs people money, and the check cannot tell you about it. Bank of America’s own routing-number page lists three numbers against a single account: one for electronic payments, one for paper, and one for wire transfers. Pick California and the first two match — 121000358 — while the wire number does not: 026009593. Nothing on the check reveals that split.

There is also more than one ACH number to be wrong about. The bank files 148 routing numbers in the Federal Reserve ACH directory extract behind this site — more than any other institution in it — and says plainly that “routing numbers are based on the state in which the account was opened”, so yours may not match where you live now.

What three banks publish on their own routing-number pages
BankACH, direct deposit and paperDomestic wire
Bank of America121000358026009593
Chase—021000021
Wells Fargo121000248—

Bank of America’s ACH and paper number is state-based; 121000358 is the number shown for an account opened in California, and 026009593 is its wire number for every state. Chase publishes 021000021 for domestic wires and no single ACH number — the Federal Reserve directory lists 51 routing numbers under JPMorgan Chase. Wells Fargo publishes 121000248 without splitting it by payment type, plus 102307164 for Brokerage Cash Services. Each bank’s own routing-number page, retrieved 8 August 2026. Confirm with the receiving bank before funding — routing numbers change.

How to verify a routing number before money moves

Four checks, in the order that catches the most errors for the least effort.

  1. Read it off a check, not a deposit slip

    The nine digits at the bottom left. IRS Form 8888 specifically flags the case where the routing number on a deposit slip differs from the one on your checks — if they disagree, the bank decides which is right, not you.

  2. Run the check-digit test

    Weight the digits 3-7-1-3-7-1-3-7-1, add the products, confirm the total divides by 10. A failure means a digit was mistyped or transposed — not one of the 18,198 numbers in the Federal Reserve directory extract behind this site fails it.

    30 sec

  3. Match it to a named institution

    A valid check digit only proves the number is well-formed. Look it up and confirm the name that comes back is the bank you expect, in a state that makes sense for the account.

  4. Ask the bank when the payment type is unusual

    Wires, brokerage accounts and some payroll systems route differently. The number on the check answers for direct deposit and ACH; for anything else it is worth one phone call before the money leaves.

    Bank of America publishes a separate wire number; Wells Fargo publishes a separate one for Brokerage Cash Services.

Typing a bank name returns every routing number that bank files; pasting nine digits returns the institution and the city on record for it.

Two official checks exist outside this site, and both have edges worth knowing. The American Bankers Association’s lookup returns “the name of the financial institution and the locations associated with that routing number” and is run by “the Official Routing Number registrar, LexisNexis Risk Solutions” — but it allows “no more than two lookups per day” and “ten lookups per month”, which is not enough to verify a payroll file. The Federal Reserve’s E-Payments Routing Directory is “updated daily, generally by 5:00 a.m. (Eastern Time)” and carries separate searches for FedACH participants and for Fedwire participants. That the Fed keeps two directories is itself the reason a bank can have one number for ACH and another for wires.

Routing numbers on checks: common questions

Where exactly is the routing number on a check?
Bottom left, as the first nine-digit block of the magnetic code line. Wells Fargo describes the order as account number “to the right of the routing number and to the left of the check number”. The IRS adds a caveat worth taking seriously: on its own sample check it notes that the routing and account numbers may be in different places on your check, so identify the routing number by its length — exactly nine digits — rather than by position alone.
How many digits is a routing number?
Nine, always. IRS Form 8888 states it as a rule: “The routing number must be nine digits. The first two digits must be 01 through 12 or 21 through 32.” Anything longer or shorter is not a routing number. If the block you are looking at has ten or twelve digits, it is almost certainly the account number.
Is the routing number the first or the last number on a check?
First. On the IRS’s own sample check the routing number leads the bottom code line and the check number closes it — and that check number is the same one already printed in the top-right corner. The repeat is the quickest way to tell the blocks apart: whichever one matches the corner is the check number, which is why IRS Form 8888 prints “Don’t include the check number” right beside its sample.
How do I know if a routing number is real?
Two tests, and you need both. First the prefix: the leading two digits must be 01–12 or 21–32. Then the check digit: weight the nine digits 3-7-1-3-7-1-3-7-1, add the products, and the total must divide by 10. All 18,198 routing numbers in the Federal Reserve ACH directory extract behind this site pass that arithmetic, so a failure is a typo. Passing both still only proves the number is well-formed — look it up and confirm the institution name.
Is my wire routing number the same as the one on my check?
Not necessarily. Bank of America publishes 026009593 for wire transfers nationwide and a separate, state-based number for electronic and paper payments — 121000358 for an account opened in California. Chase publishes 021000021 for domestic wires into a Chase account, while the Federal Reserve lists 51 routing numbers under JPMorgan Chase. Treat the number on the check as the one for paper and ACH, and ask your bank for the wire number by name.
Can someone drain my account with just my routing number?
A routing number on its own identifies your bank, not you. It is printed on every check that bank issues, published in the Federal Reserve’s E-Payments Routing Directory and searchable through the ABA’s own public lookup — it is not a secret and was never designed to be one. Your account number is the part that is specific to you, which is why a voided check deserves the same care as a bank statement.
Where do I find my routing number if I don’t have checks?
Ask your bank. IRS Form 8888 makes this the explicit instruction for a deposit “to a savings account that doesn’t allow you to write checks”, and the same applies to any account where a check was never issued. Do not reuse a number from a deposit slip: the IRS lists a deposit slip disagreeing with your checks as one of the three cases where you must get the number from the institution instead.
What do I give someone sending money from another country?
A SWIFT/BIC code and your account number — not your routing number. Chase states that “routing numbers are only used for transactions within the U.S.”. A BIC is eight or eleven characters under ISO 9362, with characters five and six naming the country: Chase’s is CHASUS33, Wells Fargo’s is WFBIUS6S. US banks do not issue IBANs, so if an overseas form demands one, give the SWIFT code and the account number instead.

Sources

External links open in a new tab.

  1. Form 8888, Allocation of Refund (Rev. 12-2025) — sample check, nine-digit rule, 01–12 / 21–32 prefixes, “Don’t include the check number.” — Internal Revenue ServicePage 2. The sample check prints routing 250250025, account 20202086 and check number 1234.Checked 08 Aug 2026
  2. Provide accurate routing and account numbers on Form 8038-CP to avoid delayed payments — Internal Revenue ServiceSource for “which may or may not be the same as the routing number displayed on a check”.Checked 08 Aug 2026
  3. 12 CFR § 229.2 — Definitions (Regulation CC): “routing number”, “MICR line” — Cornell Legal Information InstituteChecked 08 Aug 2026
  4. Standards Advisory: Magnetic Ink Still Required on Checks (2025) — Accredited Standards Committee X9Checked 08 Aug 2026
  5. Key to Check Services Routing Numbers — thrift and credit-union prefix bands — Federal Reserve Financial ServicesChecked 08 Aug 2026
  6. E-Payments Routing Directory — Frequently Asked Questions (daily 5:00 a.m. ET refresh; separate FedACH and Fedwire searches) — Federal Reserve Financial ServicesChecked 08 Aug 2026
  7. ABA Routing Number Lookup — registrar, results and free-lookup limits — American Bankers AssociationChecked 08 Aug 2026
  8. FAQs: How to Find Your Bank of America Routing Number — Bank of AmericaSplits electronic / paper / wire; California shows 121000358 and 121000358 and 026009593.Checked 08 Aug 2026
  9. Routing Numbers — 121000248, Brokerage Cash Services 102307164, SWIFT WFBIUS6S — Wells FargoChecked 08 Aug 2026
  10. Wire Transfer FAQs — 021000021 for domestic wires, CHASUS33 for international — ChaseChecked 08 Aug 2026
  11. SWIFT code vs. routing number — eight or 11 characters, nine digits, US-only — ChaseChecked 08 Aug 2026
  12. What is BIC? — ISO 9362 structure and Swift as registration authority — ISO/TC 68, Financial servicesChecked 08 Aug 2026
  13. FedACH directory extract behind this site — 18,198 routing numbers, 10,548 institutions — moov-io/fed (Federal Reserve ACH directory format)apps/web/data/ach/routing-index.json, generated 2 August 2026. Prefix histogram and 18,198/18,198 check-digit pass rate computed over that file on 8 August 2026.Checked 08 Aug 2026

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Where is the routing number on a check?

Bottom left, nine digits, in magnetic ink — and then four things the check does not tell you, including why your wire routing number may be a different number entirely.

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