A BSB number is a six-digit code that identifies which branch of a bank holds your account
BSB stands for Bank Sort Code (in the UK and Ireland, it's called a sort code; in Australia, it's called a BSB). The number tells the banking system exactly which physical or processing branch handles your account. When someone sends you money, the BSB directs that payment to the right place. Without it, the payment system wouldn't know whether your Barclays account is at the London branch or a different one.
The six digits break into two parts: the first four digits identify the bank itself, and the last two identify the specific branch. So if your BSB is 20-00-00, the "20" section tells the system it's a particular bank, and the "00" tells it which branch within that bank processes your account. You'll find your BSB printed on the bottom left of your cheques, in your online banking portal, or by calling your bank.
Key Takeaways
- Your BSB number is a six-digit code that identifies your bank branch and is required for receiving payments from other people or organisations.
- The first four digits identify your bank, and the last two identify your specific branch within that bank.
- You need your BSB along with your account number to give someone your full banking details for transfers or standing orders.
- BSB numbers are used only in the UK and Ireland; other countries use different routing systems like routing numbers (US) or SWIFT codes (international).
- Your BSB is not secret and does not need to be protected the way you protect your PIN or password.
Where to find your BSB number
Your BSB is printed on every cheque you receive from your bank, in the bottom left corner before your account number. If you don't have a cheque book, log into your online banking portal—most banks display your BSB on the account overview page or in a section labelled "Account Details" or "Sort Code". You can also call your bank's customer service line and ask for your sort code; they will give it to you immediately.
Some banks also print your BSB on your debit card statement or in your welcome pack when you open the account. If you're unsure which number is which, remember: BSB comes first (six digits), then your account number (usually eight digits). Together, these two pieces of information make up your full banking details.
Why you need your BSB for payments
When you receive a bank transfer from someone else—whether it's a wage payment, a refund, or money from a friend—the sender needs your BSB and account number to route the money correctly. The BSB tells their bank which UK or Irish bank branch to send the funds to, and your account number tells that branch which account within the branch receives it. Without the BSB, the transfer cannot be processed.
You also need your BSB when setting up a standing order (a regular automatic payment) or a direct debit (where a company takes regular payments from your account). The BSB ensures the payment goes to the right branch and account. If you give the wrong BSB, the payment will either be rejected or sent to the wrong account, which can delay bills or cause overdraft fees.
BSB versus account number and IBAN
Your account number is separate from your BSB. The account number is usually eight digits and identifies your specific account within your branch. Your BSB identifies the branch itself. Together, they form your complete UK or Irish banking details. If someone asks for your "sort code and account number," they're asking for both pieces.
An IBAN (International Bank Account Number) is a longer code used for international transfers. It includes your BSB and account number but adds country and bank information, making it work across borders. If you're receiving money from outside the UK or Ireland, you may need to provide your IBAN instead of just your BSB and account number. Your bank can tell you your IBAN, or you can find it in your online banking portal.
What happens if you give the wrong BSB
If you provide an incorrect BSB, the payment will either fail to process or go to the wrong account. Most modern banking systems catch errors before the money leaves the sender's account and reject the transfer with an error message. The sender then has to correct the details and try again, which delays the payment by at least a day.
In rare cases, a payment sent to the wrong BSB may reach a different account at a different branch. If this happens, you should contact your bank immediately and report the error. The bank can attempt to recover the funds, but this process can take several days or weeks. To avoid this, always double-check your BSB before giving it to someone, and ask the sender to confirm they have the correct details before they process the transfer.
BSB numbers in different countries
The BSB system is used only in the UK and Ireland. Other countries use different routing systems. In the United States, banks use a nine-digit routing number that serves the same purpose as a BSB. In Australia, the system is called a BSB as well, but the format and structure are different from the UK version. Canada uses an eight-digit transit number.
For international transfers, most countries use a SWIFT code (also called a BIC code) along with the IBAN. A SWIFT code identifies the bank itself, not the branch, and is used to route money between countries. If you're sending or receiving money internationally, your bank will tell you whether you need a SWIFT code, IBAN, or both.
Security and privacy of your BSB
Your BSB is not confidential information and does not need to be kept secret. It is printed on your cheques, which you may give to dozens of people, and it's safe to share with anyone who needs to send you money. Knowing your BSB alone does not allow someone to access your account or take money from it—they would also need your account number, and even then, they cannot withdraw funds without additional security checks.
Your PIN and online banking password, by contrast, must be kept private. These allow access to your account. Your BSB is simply a routing address, similar to a street address. Treat it the same way: it's fine to share it with people who need to send you money, but never share your PIN, password, or the full details of your account with anyone you don't trust.
Frequently Asked Questions
Can I change my BSB number?
No, you cannot change your BSB. It is determined by which branch your account is held at. If you want a different BSB, you would need to close your account and open a new one at a different branch, which is not practical. Most people keep the same BSB for the life of their account.
Do I need my BSB for online payments or card transactions?
No. Your BSB is needed only for bank transfers, standing orders, and direct debits. When you pay by debit card, credit card, or online payment services like PayPal, the merchant does not need your BSB. They process the payment through the card network or payment service instead.
What if my bank closes my branch?
If your bank closes the branch associated with your BSB, your account will be transferred to another branch and you will be given a new BSB. Your bank will notify you in advance and provide your new BSB. You should update anyone who has your old BSB (such as your employer for wage payments) with the new one.
Is a BSB the same as a SWIFT code?
No. A BSB is used for payments within the UK and Ireland only. A SWIFT code is used for international transfers and identifies the bank globally, not the specific branch. You may need both if you're receiving money from abroad—the sender uses the SWIFT code to reach your bank, and the IBAN (which includes your BSB) to reach your specific account.
Can someone steal money using just my BSB?
No. Your BSB alone cannot be used to take money from your account. A thief would need your account number as well, plus they would need to bypass your bank's security checks. Even with both pieces of information, most banks require additional verification before processing large transfers. Your BSB is safe to share.