Clearing and settlement systems

Clearing is every step involved in transferring ownership of funds except the last one: validating payment details, matching sender and receiver accounts, preparing the settlement instructions. Settlement is that last step — the moment funds actually move, accounts are debited and credited, and the transaction becomes final and irrevocable.

People use the words interchangeably; treasury cannot, because the difference is where the risk lives. Until settlement completes, either party can fail and leave the other exposed. Everything in this step — the systems, the acronyms, the infrastructure — exists to shrink or eliminate that window.

Settlement risk is sharpest in foreign exchange, because an FX deal settles in two countries at two different times. Trade euros for dollars and the euro leg settles in Frankfurt during European hours while the dollar leg waits for New York, six hours behind. Fail in that gap and one party has paid away its currency and will never receive the other side.

The risk carries the name of the bank that proved it. Herstatt Bank, a German lender, collapsed in 1974 after receiving deutsche marks on its FX deals but before delivering the dollars owed back. Counterparties who had irrevocably paid marks got nothing — a one-bank failure that exposed a structural flaw in global payments and set regulators building the safer settlement infrastructure this lesson describes.

Fifty years on, the term is still the working name for cross-currency settlement exposure — and the reason nearly every major FX trade now settles through the CLS system later in this step.

There are two basic ways to settle a day's payments between banks, and the trade-off between them is risk against cost.

The netting arithmetic is what makes DNS cheap: if Bank A owes Bank B ZMW 100 million and Bank B owes Bank A ZMW 80 million, only ZMW 20 million actually moves. But every payment waiting in that net is exposure until the evening run — so the rule follows the amounts. High values must settle gross, where the overnight exposure would be intolerable; low values can wait for the net, where the cost saving outweighs the risk.

SWIFT — the Society for Worldwide Interbank Financial Telecommunications — is the secure, standardised messaging network banks use to exchange payment instructions. The point to hold onto: SWIFT moves no money. It carries the messages that tell banks to move money through the settlement systems.

Large corporates connect to SWIFT directly through their banks — initiating payments, confirming FX deals, instructing securities settlements from their own treasury systems. Smaller firms instruct their bank, which translates into SWIFT messages. Either way the properties are the same: one worldwide format, encryption and digital signatures against fraud, membership covering most banks including all the major Zambian ones, and a timestamped log of every message — the audit trail that settles disputes.

CLS Bank was created to close the Herstatt gap. It stands in the middle of every FX trade settled through it: both banks pre-fund accounts at CLS in their currencies, and CLS then settles both legs at the same instant — debiting one side's euros and crediting its dollars simultaneously. Neither party can ever have paid without being paid. The principle is payment versus payment (PvP): the exchange happens atomically or not at all. Nearly all major FX flows settle this way now, and a treasurer trading FX should insist on it.

Securities trades have the same timing problem — securities can move before cash, or cash before securities, a failure the market calls a fail — and the same cure. Delivery versus payment (DvP) puts a central securities depository or central counterparty between buyer and seller and transfers the securities and the cash at the same moment; if either side cannot complete, neither transfer happens.

Both are instances of one idea: the central counterparty (CCP). For every trade the CCP becomes the buyer to the seller and the seller to the buyer, so each party faces only the CCP — regulated, well-capitalised, protected by daily mark-to-market, margin collection and a default fund — instead of each other's credit. CLS does it for FX, clearing houses like LCH for derivatives, national depositories for securities.

The Bank of Zambia oversees the country's systemically important payment systems, and the three main ones map exactly onto the gross/net distinction.

The routing rule for a Zambian treasury follows directly: ZIPSS for urgent, high-value payments; EFT for the routine payroll-and-suppliers run; cheques only where unavoidable, since even at T+1 they are the slowest and riskiest instrument. Settlement conventions like T+1 and T+2 are simply the market's agreed clearing time — trades must be validated, matched and routed, which is why securities settle a day or two after dealing, and why your cash from a sale is not spendable the moment you hit sell. Systems penalise fails — the party that doesn't deliver on time pays interest or fines.

Two operational details complete the picture. Every system has a cut-off time: an instruction submitted after it settles the next day, so a payment promised for this afternoon must be submitted before the bank's cut-off — often noon — or the promise is broken. And banks offer daylight overdrafts: an account may swing negative intraday against payments due, provided collections restore it by close of business — a fee-bearing facility, because the bank carries intraday risk while the account is short.