BACS
Bacs (Bankers' Automated Clearing Services) is a long-established UK payment system used for electronic bank-to-bank transfers, best known as the network behind Direct Debit and Direct Credit.
How it works. Bacs processes payments on a three-working-day cycle: instructions are submitted on the first day, processed on the second, and funds settle on the third. That makes it slower than real-time alternatives, but its scale, reliability and low cost make it the default rail for high-volume, non-urgent and recurring payments across the UK. Millions of payments run over it every working day, and its predictability is precisely what makes it suited to planned, scheduled money movement rather than one-off urgent transfers.
The two core services. Bacs supports two main payment types. Direct Debit lets an organisation collect variable or recurring amounts from a customer's account under a pre-authorised mandate — the mechanism behind most subscription, utility and insurance billing. Because the payer authorises the arrangement once, the biller can then collect on an agreed schedule, with protections in place should a payment be taken in error. Direct Credit (a "Bacs payment") pushes funds from an organisation to a recipient, used most commonly for payroll, supplier settlements, pensions and benefits — any case where a business pays many people or suppliers on a regular cycle.
Where it fits. For organisations moving money at scale, Bacs remains the workhorse of UK payments precisely because it is predictable and inexpensive. Faster Payments has taken over where speed matters, and CHAPS handles high-value same-day transfers — but for regular, planned, batched payments such as paying staff or collecting subscriptions, Bacs is still the standard. It operates as part of the UK's regulated payments infrastructure and is used by banks, corporates and payment providers alike. In practice most organisations use a mix: Bacs for the predictable bulk of recurring payments, faster rails for anything urgent.