Generate UK IBAN
Your UK IBAN:
Validate IBAN
Validation Result:
How to Use This Calculator
Enter Your Sort Code: Type your 6-digit UK bank sort code with or without hyphens (e.g., 20-04-15 or 200415).
Provide Account Number: Enter your 8-digit bank account number. If your account has fewer digits, add leading zeros.
Select Your Bank: Choose your bank from the dropdown menu. This helps generate the accurate 4-letter bank code required for UK IBANs.
Generate or Validate: Click the button to either create a new IBAN or verify an existing one. Results appear instantly with a detailed breakdown.
UK IBAN Structure Explained
A UK IBAN consists of 22 characters organised in a specific format. Each section serves a distinct purpose in identifying your bank account internationally.
| Component | Position | Length | Example | Purpose |
|---|---|---|---|---|
| Country Code | 1-2 | 2 letters | GB | Identifies United Kingdom |
| Check Digits | 3-4 | 2 digits | 29 | Validates IBAN accuracy |
| Bank Code | 5-8 | 4 letters | NWBK | Identifies the bank |
| Sort Code | 9-14 | 6 digits | 601613 | Identifies branch |
| Account Number | 15-22 | 8 digits | 31926819 | Identifies your account |
Check Digit Calculation Method
The IBAN check digits use the MOD 97 algorithm, an internationally standardised method defined in ISO 7064. This mathematical process verifies the integrity of the entire IBAN sequence.
Form the Basic Bank Account Number (BBAN) by combining the bank code, sort code, and account number.
Create a temporary string starting with “GB00” followed by the BBAN.
Move “GB00” from the beginning to the end of the string.
Replace each letter with its numerical equivalent (A=10, B=11, C=12… Z=35).
Calculate the modulo 97 of this number. Subtract the result from 98 to get your check digits.
Error Detection
The MOD 97 method catches 99.97% of transcription errors, including swapped digits and incorrect characters.
Global Standard
This algorithm is used across all countries that implement IBAN, maintaining consistency in international banking.
Automated Verification
Banks process the check digits automatically during transfers, rejecting invalid IBANs before processing.
Where to Find Your IBAN
Bank Statements
Your IBAN appears at the top of paper statements and in the account details section of online statements.
Online Banking
Log into your online banking portal and navigate to account details or settings to view your IBAN.
Mobile Banking Apps
Most banking apps display your IBAN in account information, often with a convenient copy button.
Bank Cards
Some banks print the IBAN on debit cards, though this varies by institution.
Customer Service
Contact your bank directly via phone or branch visit to request your IBAN details.
Calculate It
Use this calculator with your sort code and account number to generate your IBAN instantly.
When You Need an IBAN
IBANs are required for specific types of international banking transactions, particularly within Europe and certain other regions.
| Transaction Type | IBAN Required | Additional Details |
|---|---|---|
| SEPA Transfers | Yes | Mandatory for all Single Euro Payments Area transactions |
| EU Bank Transfers | Yes | Required when sending money to European Union countries |
| International Payments | Usually | Many countries worldwide now use IBAN format |
| Receiving Foreign Payments | Yes | Provide your IBAN to receive international transfers |
| UK Domestic Transfers | No | Sort code and account number sufficient for UK-to-UK |
| Setting Up Direct Debits | Sometimes | Some international services request IBAN for direct debits |
Common Mistakes and How to Avoid Them
Incorrect Sort Code
Double-check your sort code has exactly 6 digits. Remove any hyphens or spaces when entering it into forms.
Missing Leading Zeros
If your account number has fewer than 8 digits, add zeros at the beginning (e.g., 12345 becomes 00012345).
Wrong Bank Code
The 4-letter bank code must match your actual bank. Selecting the wrong bank generates an invalid IBAN.
Transposed Digits
Carefully verify each digit when copying your IBAN. Swapping two numbers creates an entirely different account.
Including Spaces
When submitting IBANs online, remove all spaces. Many systems require continuous characters without formatting.
Using Old Details
After changing banks or accounts, generate a fresh IBAN. Old IBANs become invalid once accounts close.
IBAN vs BIC/SWIFT Code
| Feature | IBAN | BIC/SWIFT |
|---|---|---|
| Purpose | Identifies individual bank account | Identifies the bank and branch |
| Length | Up to 34 characters (22 for UK) | 8 or 11 characters |
| Format | Letters and numbers | Letters and numbers |
| Required For | European and some international transfers | Most international transfers |
| UK Example | GB29NWBK60161331926819 | NWBKGB2L |
| Uniqueness | Unique to your specific account | Shared by all customers at same branch |
For international transfers, you often need both. The BIC/SWIFT code routes the payment to the correct bank, while the IBAN ensures it reaches your specific account.
Frequently Asked Questions
Can I use an IBAN for UK domestic payments?
UK domestic payments typically use sort code and account number rather than IBAN. However, most UK banks accept IBAN format for domestic transfers as well. The payment system automatically extracts the sort code and account number from positions 9-22 of your IBAN. Using IBAN domestically works but is unnecessary for UK-to-UK transactions.
How long does an IBAN remain valid?
Your IBAN remains valid as long as your bank account stays open. If you close your account, switch banks, or your bank merges with another institution, your IBAN changes. Always verify your current IBAN before providing it for incoming payments, especially if you have not used it recently. Most banks notify customers of IBAN changes during account transitions.
What happens if I provide an incorrect IBAN?
Banks validate IBANs using check digits before processing transfers. If the check digits do not match, the bank rejects the payment immediately and returns funds to the sender. If the IBAN passes validation but belongs to a different account, the money may be sent to the wrong recipient. Recovery becomes difficult and time-consuming. Always double-check your IBAN before sharing it.
Do all UK banks use the same IBAN format?
Yes, all UK IBANs follow the same 22-character structure: GB + 2 check digits + 4-letter bank code + 6-digit sort code + 8-digit account number. The bank code varies between institutions (NWBK for NatWest, BARC for Barclays, etc.), but the overall format remains consistent. This standardisation enables automated processing across the UK banking system.
Can I have multiple IBANs for one account?
No, each bank account has exactly one IBAN. The IBAN uniquely identifies your specific account at your specific branch. If you hold multiple accounts at the same bank, each account receives its own distinct IBAN with different account numbers. Joint accounts share a single IBAN between account holders.
Why does my IBAN start with GB instead of UK?
IBAN country codes follow the ISO 3166-1 alpha-2 standard, which assigns “GB” to Great Britain rather than “UK” for United Kingdom. This code covers England, Scotland, Wales, and Northern Ireland. The GB designation has been used in international banking standards since IBAN implementation and remains unchanged despite common usage of “UK” in other contexts.
Is it safe to share my IBAN publicly?
Yes, sharing your IBAN is generally safe. IBANs are designed for receiving payments, and knowing someone’s IBAN does not allow withdrawals from their account. However, avoid posting your IBAN alongside other personal details like your full name, address, and date of birth, as this combination could potentially be used for identity verification fraud. Share your IBAN only with trusted parties who need to send you money.
Do online banks and fintech companies have IBANs?
Yes, UK-registered digital banks like Monzo, Starling, and Revolut issue IBANs following the same format as traditional banks. These IBANs function identically for receiving international payments. Some fintech companies partner with established banks to provide IBAN accounts, while others hold their own banking licences. Always verify that your digital bank provides a UK IBAN (starting with GB) rather than an EU IBAN if you need UK-based banking services.
How do I find my bank code if it is not listed?
The bank code is derived from the first four characters of your bank’s BIC/SWIFT code. You can find this on your bank statement, online banking portal, or by contacting customer service. Alternatively, look up your sort code in an official UK sort code directory, which typically lists the associated BIC code. Major UK banks publish their BIC codes on their websites.
Security and Privacy Considerations
Receiving Payments Only
IBANs can only be used to send money to your account, not withdraw from it. This makes them safe for sharing with payment senders.
No Authentication Required
Unlike card numbers, IBANs do not require CVV codes, PINs, or passwords. They simply route payments to your account.
Bank Verification
Banks verify IBANs automatically during payment processing, rejecting invalid formats before funds transfer.
Phishing Awareness
Legitimate banks never request your IBAN via email or text. Provide it only through secure channels for expected payments.
Statement Monitoring
Regularly review bank statements for unexpected incoming payments, which could indicate someone using your IBAN incorrectly.
Secure Transmission
When sending your IBAN electronically, use encrypted email or secure messaging platforms rather than unprotected channels.
IBAN in Different Regions
While UK IBANs follow a 22-character format, other countries implement different structures based on their domestic banking systems.
| Country | Code | Length | Example Format |
|---|---|---|---|
| United Kingdom | GB | 22 | GB29NWBK60161331926819 |
| Germany | DE | 22 | DE89370400440532013000 |
| France | FR | 27 | FR1420041010050500013M02606 |
| Spain | ES | 24 | ES9121000418450200051332 |
| Italy | IT | 27 | IT60X0542811101000000123456 |
| Netherlands | NL | 18 | NL91ABNA0417164300 |
| Ireland | IE | 22 | IE29AIBK93115212345678 |
| Switzerland | CH | 21 | CH9300762011623852957 |
References
Bank for International Settlements (2023). “Committee on Payments and Market Infrastructures – IBAN Implementation.” Basel: BIS Publications.
European Committee for Banking Standards (2023). “IBAN Registry – Technical Specifications and Standards.” Brussels: ECBS Technical Board.
Pay.UK (2023). “Standard Format of the IBAN Issued in the United Kingdom.” London: Pay.UK Standards Documentation.
SWIFT (2023). “IBAN Registry – Release 94.” La Hulpe, Belgium: Society for Worldwide Interbank Financial Telecommunication.
International Organization for Standardization (2022). “ISO 13616-1:2020 – Financial services — International bank account number (IBAN).” Geneva: ISO Standards.
UK Finance (2023). “Payment Systems and Infrastructure – IBAN Guidelines for UK Banks.” London: UK Finance Publications.