IBAN, SWIFT/BIC, routing numbers, and local bank details explained

A client asks for a SWIFT code. Your receiving instructions show an account number and routing number. Another client asks for an IBAN, while a customer in Mexico mentions a CLABE.

These are not alternative names for one universal account number. They identify different parts of a payment arrangement.

Some identifiers locate an account, some identify an institution, and some act as aliases or allocation references. Understanding the distinction helps you select the right transfer form and recognise when the requested method does not match your receiving instructions.

This guide explains the fields across six currencies without supplying example numbers that could be mistaken for real payment destinations.

Start with the route, not a missing field

Before searching for a code, confirm the currency and transfer method the receiving provider actually supports.

A bank form requesting a BIC may be configured for an international transfer while your USD instructions support only a specified domestic route. Adding a code found online does not make the receiving product accept that international service.

Likewise, an IBAN-format identifier does not establish every supported incoming payment method. Account format and product capability are separate.

Use the current complete instructions from the receiving provider. If the payer cannot use them, ask for an approved alternative rather than constructing one from unrelated banking information.

Compare the identifiers at a glance

Identifier	Main role	Common context
IBAN	Standardised account identifier	Accounts in countries using the IBAN standard
BIC, often called a SWIFT code	Identifies an institution or business party	Financial messaging and relevant bank-transfer instructions
ABA routing number	Identifies a US financial institution	Supported US payment arrangements
Account number	Identifies an account within the relevant arrangement	Used alongside other route-specific details
Sort code	Identifies the relevant UK routing arrangement	UK account-transfer instructions
CLABE	Standardised Mexican bank-account identifier	Supported MXN transfers
Pix key	Alias associated with receiving-account information	Supported Brazilian Pix payments
Bre-B Llave	Identifier linked to a receiving destination	Supported Colombian Bre-B payments

A payment reference is another field again. It can identify the customer, invoice, or allocation needed by the receiving service. Do not substitute one of these identifiers for a required reference.

What is an IBAN?

IBAN means International Bank Account Number. It is a standardised structure for identifying an account in countries that use the standard, with country-specific formats recorded in the official registry.

Swift serves as the registration authority for the IBAN standard and publishes relevant information. The structure is not identical in length and composition across every country. Swift: IBAN standard.

A format or checksum check can catch certain entry errors. It does not prove who controls the account, whether the account is active, or whether your receiving product accepts the chosen method.

Also distinguish an IBAN from the legal account relationship. A virtual IBAN may be part of a provider’s allocation arrangement; its format alone does not establish that you hold a conventional deposit account. See virtual accounts explained.

What is a BIC or SWIFT code?

BIC means Business Identifier Code. It identifies a party under the relevant standard and is commonly referred to as a SWIFT code in payment interfaces. It is not the beneficiary’s individual account number. Swift: BIC standard.

A route can require an account identifier and institution information together. Some payment forms derive information automatically; others ask for additional fields.

Do not use a bank’s general website BIC as a substitute for the exact instructions supplied for your receiving arrangement. A provider may specify a particular institution or intermediary setup, or may not support the international route at all.

The SEPA versus SWIFT guide explains the difference between a payment scheme and messaging infrastructure.

For a reference lookup, use the SWIFT code finder to browse by country, institution, and city, or the SWIFT/BIC checker to examine a code you already have. A directory match is not confirmation of account ownership or current payment eligibility; verify the bank’s complete receiving instructions.

What is a US routing number?

An ABA routing number is a nine-digit identifier associated with a US financial institution. The American Bankers Association provides routing-number information and lookup resources. ABA: Routing numbers.

The routing number and the account number perform different jobs. The first helps identify the relevant institution; the second identifies the account within the receiving arrangement.

Use the routing number specified for the actual transfer method. Do not assume that instructions supplied for one service are interchangeable with all other ACH or wire instructions associated with a bank.

A lookup result can help identify a routing number, but it does not verify the beneficiary or authorise the payment. If the sender’s bank does not recognise a number, ask it and the receiving provider to resolve the issue using the issued instructions.

How do UK sort codes and account numbers fit together?

For many UK account transfers, the payer supplies the beneficiary name, sort code, and account number, along with any required reference.

Pay.UK’s Confirmation of Payee guidance describes name checking using relevant account details, with additional information for some arrangements. A check result needs to be interpreted through the payer’s provider. Pay.UK: Confirmation of Payee FAQs.

A name mismatch should be investigated rather than dismissed because the account number looks familiar. Use the exact approved beneficiary name and confirm the intended recipient through an established channel.

Also verify the method. UK account details do not automatically promise that a receiving product supports every Faster Payments, Bacs, CHAPS, or international arrangement. See the GBP guide.

What is a Mexican CLABE?

A CLABE is an 18-digit standardised bank-account identifier used in Mexico. Banco de México explains its role in SPEI payment instructions, alongside other supported identification options in participating services. Banco de México: SPEI.

A CLABE is not the same as a card number, invoice reference, or SPEI tracking key. The tracking key identifies a payment event; the receiving identifier directs the payment.

Copy the complete value from the approved receiving instructions. Do not remove leading zeros or treat it as a spreadsheet quantity that may be reformatted.

The MXN and SPEI guide explains tracking and confirmation after a payment has been sent.

How do Pix keys and Bre-B Llaves differ from account numbers?

These identifiers can make a local payment easier to address by linking an alias to the underlying receiving arrangement. They are not separate currencies or login credentials.

A Pix key or Bre-B Llave must be valid for the actual route and recipient. A personal identifier used with one financial institution is not automatically suitable for a business collection product elsewhere.

Follow the issued instructions and inspect the recipient information presented before authorisation. Do not assume a familiar phone number or email address proves the current linked destination is correct.

For the central-bank definitions and practical workflows, see the Pix guide and Bre-B guide.

Keep references and intermediary instructions distinct

An allocation reference can be essential even when the account details are otherwise correct. It tells the receiving arrangement how to associate the transfer with the intended customer or obligation.

An intermediary bank field, by contrast, describes part of a supported transfer route. It is not a place to insert an invoice number or a receiving-provider support email.

Use only the intermediary instructions actually supplied for the route. Do not invent them because the payer’s form includes an optional field.

If the provider requires an exact reference, preserve it and keep your invoice allocation in a separate record where necessary. Our payment references guide covers truncation, missing values, and duplicate amounts.

Protect identifiers from accidental formatting changes

Treat account identifiers as text when preparing spreadsheets or documents. Numeric formatting can remove leading zeros or display long values in scientific notation.

Avoid copying instructions from screenshots when a reliable text source is available. After copying, compare the full value with the approved source, including any required letters and leading zeros.

Do not silently “correct” a name or identifier because it looks unfamiliar. Ask the provider to explain it.

When transmitting instructions, include the currency and method beside the identifiers. A copied account number detached from its route is easier to misuse later.

Validate the recipient, not just the syntax

A mathematically valid identifier can still direct payment to the wrong party. A real bank code can appear on a fraudulent invoice.

Verify new or changed destinations through a previously established contact method. Match the commercial obligation, legal supplier, authorised request, and actual receiving instructions.

Never provide passwords, authentication codes, recovery phrases, or remote access to help someone “verify” ordinary receiving details. Those are not fields required to send you a legitimate payment.

Use the payment-fraud guide for a proportionate verification process and the vendor-onboarding checklist for business supplier records.

Troubleshoot a field mismatch before sending

If the payer’s form requests an identifier you do not have, first check the selected country, currency, transfer type, and account type. A mismatch there can produce the wrong set of fields.

Then ask the receiving provider whether that sending route is supported. Give it the relevant field names and method without exposing credentials or unrelated account information.

If the route is incompatible, obtain a different approved arrangement. Do not use random placeholder values to pass validation or borrow another customer’s instructions.

For payments already sent, retain the exact instruction used and request route-specific evidence. Changing the stored destination afterwards does not redirect a transfer already in progress.

Frequently asked questions

Can I calculate an IBAN from any account number?

No universal conversion applies. Use the identifier officially issued for the actual account arrangement rather than building one yourself.

Is a SWIFT code the same as a routing number?

No. They belong to different identification systems and perform different roles in the relevant payment arrangements. Follow the route-specific instructions.

Does a valid identifier prove the account belongs to my supplier?

No. Format validity and recipient ownership are different checks. Verify the destination and authorised payment request independently.

Should I publish complete receiving details on a public website?

Use an appropriate channel for legitimate payers and your provider’s guidance. Publicly exposing every detail is not necessary for an invoice handover, and credentials must never be included.