What a sort code identifies
A UK sort code is a 6-digit number, usually written as three pairs separated by hyphens (for example, 20-00-00), that identifies the specific bank and branch where an account is held. Paired with an 8-digit account number, this combination is all that's needed to make a domestic payment within the UK.
The sort code system predates modern electronic banking by a long way — it was originally used to route paper cheques to the correct physical branch for clearing, and the format has simply carried forward into the digital era.
Sort code vs account number — what each one does
Sort code (6 digits) — identifies the bank and branch. The first two digits often (though not always reliably) indicate the bank itself, since major UK banks were historically allocated specific number ranges.
Account number (8 digits) — identifies the specific account at that branch.
Together, these two numbers are equivalent to what an IBAN does in one combined string for most of Europe — the UK simply kept its details as two separate numbers rather than merging them into a single standardized format.
Do UK accounts have IBANs?
Yes, technically — every UK account can have an IBAN calculated from its sort code and account number, and you may be asked for it when receiving a payment from certain international senders, particularly from Eurozone countries. A UK IBAN follows the standard format: starts with GB, followed by two check digits, then a 4-character bank code, the 6-digit sort code (with no hyphens), and the 8-digit account number — for a total of 22 characters.
However, for the much more common case of paying a UK supplier, you'll typically only be given the sort code and account number directly, since this is what domestic UK payment systems actually use.
How domestic UK payments work: BACS, Faster Payments, and CHAPS
The UK has three main domestic payment systems, and which one is used affects speed and cost:
Faster Payments — the standard for most everyday UK bank transfers today. Payments typically arrive within seconds to a couple of hours, and it's available 24/7 including weekends. This is what most banking apps default to for a standard bank transfer.
BACS — an older, batch-based system mainly used for things like payroll and direct debits. Payments typically take three working days to clear, and it's processed only on business days.
CHAPS — used for same-day, high-value, or time-critical domestic payments, such as property transactions. It carries a fee (often more than Faster Payments) but guarantees same-day settlement if submitted before the bank's cutoff time.
For paying a UK supplier's invoice, Faster Payments is almost always the default and most practical choice if you're paying from a UK account.
Paying a UK supplier from outside the UK
If you're sending money into the UK from abroad, you won't use BACS, Faster Payments, or CHAPS directly — these are domestic UK networks. Instead, an international wire will typically need:
The supplier's UK sort code and account number (or their UK IBAN, if they've provided one), and the receiving bank's SWIFT/BIC code, since this is what routes the payment internationally before it lands in the UK's domestic clearing system.
Some UK banks will provide their SWIFT/BIC code directly alongside standard sort code and account number details specifically for this reason — it's worth asking your supplier if it isn't already included on their invoice.
A common point of confusion
Because the UK uses a sort code and account number for everyday domestic transfers but a SWIFT/BIC for international ones, it's easy for an overseas payer to mistakenly try to use just the sort code and account number when initiating an international wire — this will typically be rejected or significantly delayed, since most international wire systems are built expecting either an IBAN or a SWIFT/BIC, not a UK-specific sort code format. Always confirm with your bank or payment provider exactly which details they need for the specific payment route you're using.
Once the payment details are sorted
Getting the routing right means your payment arrives at the correct account without delay. The next thing worth thinking about for any GBP invoice priced from abroad is timing the actual currency conversion — GBP pairs can move meaningfully within a single week, and converting on a good day versus a bad one makes a real difference on a sizeable payment.
See how Easier FX tracks your GBP invoices and flags good timing to convert →