Bank sort code checker: confirm a code before you pay

A check that is worth running

1. Confirm the shape. Six digits, nothing more and nothing less. A code with a letter in it, or with five or seven digits, has been mistyped or is not a UK sort code at all, and no further checking is needed.
2. Confirm the bank, not the branch. The first two digits name the clearing bank or group. If the invoice says one bank and the code belongs to another, that is a real signal. If the branch address looks odd, that is usually nothing, because branch records lag closures by years.
3. Run the pair through modulus checking. A sort code and account number together can be tested arithmetically under the scheme's own rules. This catches transposed digits and nothing else, but transposed digits are the commonest honest error in the whole process.
4. Then use Confirmation of Payee. Type the payee's name into your own bank's payment screen and read what it says back. This is the only step that compares a name to an account, and it is the step that catches a fraudulent change of details that passes every other test.

What a checker is actually looking at

Behind almost every free sort code checker is the Extended Industry Sort Code Directory, the industry's own reference file, which is a licensed product. That is why the checkers agree with each other, why they all show the same branch address, and why they all go stale at the same rate. It also means the answer they give you is a record about a bank branch rather than a statement about an account, and no amount of lookup will convert one into the other.

The failure this is usually meant to prevent

Invoice redirection works by changing the bank details on a genuine-looking invoice from a supplier you really use. Every detail on that invoice checks out because the fraudster supplies a real sort code for a real bank and a real account they control. A sort code checker returns a clean result, and the money is gone. The controls that actually bite are name matching at the moment of payment, and a telephone call to a number you already had, never one printed on the new invoice.

Why this index does not offer a full lookup

Republishing a licensed directory would make this site a reseller of somebody else's file, and it would not be honest about where any entry came from. Instead the index reads what each bank publishes itself and quotes it with a date. That covers far fewer codes than a directory, and every row it does carry can be traced to a page the bank wrote. Where you need the branch behind an arbitrary code, your own bank can tell you, and its answer is the one the payment system will use.

Questions people ask

Does a clean check mean the account is safe to pay?

No. It means the code names a real bank. The account behind it can belong to anyone, including someone impersonating your supplier.

Is there a free official checker?

Not for the public. The industry file is licensed. Your own bank's payment screen, with Confirmation of Payee, is the free check that matters most.

What is modulus checking?

An arithmetic test run on a sort code and account number together under rules published by the payment scheme. It confirms the pair is well formed. It does not confirm the account exists.

The same question in the other market

• Sort code checker across the index
• SWIFT code across the index
• Bank identification code across the index
• Account number across the index
• IBAN number UK across the index