A BSB is a six-digit code that identifies which branch of a bank holds your account
BSB stands for Bank Sort Code, and it is a number used in the United Kingdom and Ireland to route money to the right bank branch. Think of it like a postal code for your bank — it tells the payment system exactly which physical location or processing centre handles your account. Every bank branch has its own BSB, and you will need it whenever someone sends you money or when you set up a payment to leave your account.
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 "20-00" part means it is a particular bank, and the final "00" means it is their main processing centre or a specific branch location. You will usually see it written with hyphens (20-00-00) or without (200000) — both mean the same thing.
If you are new to UK or Irish banking, you will encounter BSB codes on cheques, bank statements, and whenever you need to receive a bank transfer. It works alongside your account number — the two together tell a payment system where your money should go.
Key Takeaways
- A BSB is a six-digit code that identifies your bank branch and is required for receiving bank transfers and setting up payments.
- The first four digits identify the bank, and the last two identify the branch or processing centre.
- You can find your BSB on your cheque book, bank statement, or by logging into your online banking.
- BSB codes are used only in the United Kingdom and Ireland; other countries use different routing systems.
- You need both your BSB and account number together for someone to send you money by bank transfer.
Where to find your BSB number
Your BSB is printed on every cheque in your cheque book, in the bottom left corner before your account number. If you do not have cheques or prefer not to look them up that way, log into your online banking and check your account details — most banks display it prominently on the account summary page or in a section called "Account Details" or "Sort Code".
You can also call your bank's customer service line and ask them to confirm your BSB. Have your account number or card details ready so they can verify who you are. Some banks also print it on bank statements, though not all do.
If you are setting up a new account and have not received your cheque book yet, ask the bank directly during the account opening process. They will give you the BSB when ready — you do not have to wait for anything to arrive in the post.
Why banks ask for both BSB and account number
The BSB alone is not enough to send you money. Your bank needs both pieces of information because the BSB only identifies the branch, not your individual account within that branch. Imagine a large supermarket with many tills — the BSB tells you which supermarket, but the account number tells you which till to put the money into.
When you give someone your details for a bank transfer, always provide both your BSB and your account number. If you give only one, the payment will fail or be delayed while the bank tries to work out where it should go. Most payment forms ask for both together and will not let you submit without them.
How BSB codes differ from other countries' systems
The BSB system is specific to the United Kingdom and Ireland. If you are sending money to or receiving money from another country, that country will use a different routing system. The United States uses a nine-digit routing number; Australia uses a six-digit BSB code (which works the same way but is a different system); Canada uses an eight-digit transit number.
For international transfers, you will usually need an IBAN (International Bank Account Number) or a SWIFT code instead of a BSB. An IBAN is a longer code that includes your country, bank, and account information all in one. If you are moving money between countries, ask your bank which code the receiving country needs — do not assume a BSB will work outside the UK and Ireland.
What happens if you give the wrong BSB
If you provide an incorrect BSB, the payment will usually be rejected before it leaves the sending bank. Modern banking systems check that the BSB and account number match before processing the transfer, so the money straightforward will not go through. The person sending you the money will be told the payment failed and can try again with the correct details.
In rare cases, a payment might go to the wrong branch of the same bank. If this happens, the bank will usually catch it and send it back to the sender, or contact you to ask if the payment was meant for you. The important thing is that your money will not disappear — the banking system is designed to prevent that.
Always double-check your BSB before giving it to someone, especially for large payments. It takes only a moment and prevents the frustration of a failed transfer.
BSB codes and online banking security
Your BSB is not secret information — it is safe to share it with anyone who needs to send you money. It is printed on your cheques, which you may hand to shops or individuals, and it is not sensitive in the way your PIN or password is. However, you should never share your full account details (BSB plus account number) with anyone unless you are certain they are legitimate and need it for a genuine payment.
Scammers sometimes ask for BSB and account number as part of a fraud attempt. If someone contacts you unexpectedly asking for these details, do not give them out. Your bank will never ask for your account number or BSB by email or phone unless you have called them first. If you are unsure, hang up and call your bank directly using the number on the back of your card.
Frequently Asked Questions
Can I change my BSB?
No, your BSB is fixed to the branch where your account is held. If you want a different BSB, you would need to move your account to a different branch, which most people do not do. If you have moved house, you can usually keep your current account and BSB even if there is a closer branch now.
Do I need my BSB for online payments?
For payments within the UK using Faster Payments or BACS, you will need your BSB and account number. For some online services like PayPal or Stripe, you may only need your account number because the system already knows your bank. Check what the payment form asks for.
What if my bank has closed the branch with my BSB?
Your BSB remains valid even if the physical branch closes. The bank reassigns the code to a processing centre, and payments continue to reach your account normally. You do not need to do anything or update your details.
Is a BSB the same as a sort code?
Yes, BSB and sort code mean the same thing. "Sort code" is an older term, and "BSB" is more commonly used now, but banks and payment systems use both names interchangeably.
Do I need a BSB to receive money from abroad?
No. For international transfers, the sending bank will ask for your IBAN or SWIFT code instead. Your BSB only works for payments within the UK and Ireland. Ask your bank for your IBAN if you are expecting money from outside these countries.