Sort code

Sort code plus account number is the UK domestic format. Together they identify a specific UK bank account for transfers within the country: BACS direct credits and debits (which settle in 3 working days), Faster Payments (which settle in seconds to minutes), and CHAPS (same-day for high-value transfers). Internationally, the same account is identified by an IBAN that wraps the sort code and account number inside a standardised international format.

The first two digits of a sort code identify the bank: 20 is Barclays, 30 is Lloyds, 09 is Santander UK, and so on. The remaining four digits identify the specific branch (historically) or routing centre (more recently, as banks centralised). For invoicing, the practical thing is that the full 6 digits plus the 8-digit account number is enough for any UK buyer to send a domestic Faster Payment.

On UK invoices, show the sort code and account number prominently for domestic clients (most B2B UK transactions use Faster Payments). For international clients paying you into a UK account, show the IBAN and the BIC (BARCGB22 for a Barclays account, for example) instead. Some invoices show both formats so the buyer can pick whichever their bank prefers.