A sort code is a six-digit number that identifies which bank or building society holds your account

In the UK, a sort code is the routing number for your bank. It tells the financial system which specific branch or institution your account belongs to. Sort codes are written as three pairs of numbers separated by hyphens — for example, 20-17-81. You'll find yours on the bottom left of your cheques, in your online banking, or by calling your bank.

Sort codes exist because money moving between accounts needs a clear path. When someone sends you money, their bank uses your sort code to find your bank, then uses your account number to find you within that bank. Without it, the payment system wouldn't know where to send the funds. Building societies use sort codes the same way banks do.

The first two digits of a sort code identify the bank or building society. The next two identify the region or processing centre. The last two identify the specific branch. So a sort code tells the payment system: this bank, this location, this branch.

Key Takeaways

  • A sort code is a six-digit number split into three pairs that identifies your specific bank branch in the UK payment system.
  • You need your sort code whenever someone sends you money by bank transfer, standing order, or direct debit.
  • Your sort code appears on your cheques, in your online banking portal, and on statements — you can also call your bank to ask.
  • Sort codes are different from account numbers; you need both to receive a payment, but they serve different purposes in the routing process.
  • If you give someone the wrong sort code, their payment will either bounce back or go to the wrong account, so double-check before sharing it.

Where to find your sort code

The easiest place to look is a cheque from your account. The sort code sits at the bottom left, printed in magnetic ink, usually before your account number. If you don't have cheques, log into your online banking — most banks display your sort code on the account details page or in a section called "Account Information" or "Payment Details".

Your bank statement also shows your sort code, either at the top or in the account details section. If none of these options work, call your bank's customer service line. They will confirm your sort code in seconds. Some banks also print it on the back of your debit card, though not all do.

Why banks need both a sort code and an account number

Think of your sort code and account number as a two-part address. The sort code is the postcode — it narrows the destination down to one bank branch. Your account number is the house number — it identifies your specific account within that branch. Together, they form what's called your bank details.

The payment system uses the sort code first to route the money to the right bank, then uses the account number to deposit it into the right account. If you give someone only your account number, they won't know which bank to send it to. If you give only your sort code, they won't know which account within that bank to use. Both are required for a successful transfer.

This two-part system also protects against mistakes. If someone enters your sort code wrong but your account number right, the payment will go to the wrong bank and bounce back. The system catches the mismatch before money disappears.

What happens if you give the wrong sort code

If you provide an incorrect sort code, the payment will either fail or go to the wrong account. Modern payment systems in the UK use Confirmation of Payee (CoP), which checks whether the account number matches the sort code you've given. If they don't match, the payment is usually blocked and returned to the sender with a warning.

If the wrong sort code happens to belong to a real bank branch and the account number exists there, the money could land in someone else's account. This is rare because the account number would have to exist at that specific branch, but it's why accuracy matters. Always double-check the sort code before you send money or give it to someone else.

If you've sent money to the wrong sort code, contact your bank when ready. They can sometimes recall the payment if it hasn't been processed yet. The longer you wait, the harder it becomes to recover.

Sort codes for different types of accounts

Every bank account in the UK — whether it's a current account, savings account, or business account — has a sort code. The sort code doesn't change based on the account type; it identifies the bank and branch, not what you use the account for.

Some banks operate multiple sort codes for the same branch, usually for different regions or processing systems. If you have accounts at multiple banks, each will have its own sort code. If you have multiple accounts at the same bank branch, they may share the same sort code but will have different account numbers.

Building societies also use sort codes. Their sort codes work exactly the same way as bank sort codes in the payment system, so you treat them identically when sending or receiving money.

Sort codes versus other payment identifiers

The UK uses sort codes for domestic transfers. If you're sending money internationally, you'll need different information: an IBAN (International Bank Account Number) or a SWIFT code (also called a BIC code). These serve the same routing purpose as a sort code but work across borders.

Your IBAN includes your sort code within it — it's a longer number that starts with "GB" and contains your sort code plus your account number in a standardized format. Your SWIFT code identifies your bank internationally. You don't need to calculate these yourself; your bank provides them when you ask for international payment details.

For payments within the UK, use your sort code and account number. For payments to other countries, ask your bank for your IBAN or SWIFT code. Using the wrong one will cause the payment to fail or be delayed.

Frequently Asked Questions

Is my sort code the same as my account number?

No. Your sort code identifies your bank branch; your account number identifies your specific account within that branch. You need both to receive a payment. The sort code is six digits in three pairs (like 20-17-81); the account number is usually eight digits.

Can I use someone else's sort code to send them money?

Yes, if it's their correct sort code. You need their sort code and account number to send them money by bank transfer. If you have the wrong sort code, the payment will either be rejected or go to the wrong account, so always confirm both details before sending.

Do I need to memorize my sort code?

No. You only need to know where to find it — on a cheque, in your online banking, or by calling your bank. Most people look it up when they need it rather than memorizing it. Write it down or take a photo of it if you'll be using it repeatedly.

What if my bank closes my branch — does my sort code change?

Usually not. When a bank closes a branch, it typically reassigns accounts to another branch, but the sort code often stays the same to avoid disrupting existing payments and standing orders. Your bank will tell you if your sort code changes, which is rare.

Can I find someone's bank from their sort code?

Yes, sort codes are public information. You can look up which bank a sort code belongs to using the UK's sort code directory or by searching online. This is useful if you receive a payment and want to know which bank it came from, but the sort code alone doesn't identify the person — you'd need the account number for that.