How CLS makes currency trades safer: PvP, netting and timing

The problem: one side can pay before the other pays back

Foreign exchange—FX for short—is the business of swapping one currency for another. In the simplest version, known in the market as a spot trade, two institutions agree to exchange, say, dollars for yen at an agreed rate. But the two sides of that swap do not take place in the same place at the same time. The dollars move through banks in New York; the yen move through banks in Tokyo. If one payment goes out before the other arrives, one party is exposed for the full value of the trade.

This is called FX settlement risk, and its most famous name is Herstatt risk. In June 1974, Bankhaus Herstatt, a German bank, was closed by regulators in the middle of a settlement day. It had already received Deutsche marks from its trading partners, but its US dollar payments never went out. Those partners had paid in full and received nothing back. The shock froze trust between banks and nearly brought cross-border payments to a halt. It was a vivid reminder that in a market where trillions change hands, the dangerous moment is not the trade itself—it is the settlement.

Payment versus payment: the idea that changed FX settlement

Settlement is the moment when currencies are actually transferred. CLS, which began operating in 2002, is the market’s main answer to settlement risk. It is a bank, owned by a group of major financial institutions, and it acts as a trusted third party at the centre of currency settlement. Today, it settles more than USD 8 trillion in payments a day in 18 currencies. Its method is called payment versus payment, or PvP.

PvP works like a perfect handshake. The final payment in one currency is released only at the same moment as the final payment in the other currency. If one side cannot pay, neither side pays. In everyday life, we solve this kind of problem by handing over the cash and the keys at the same time; across different countries and time zones, it takes a dedicated bank to do it.

This removes what bankers call principal risk—the risk of losing the entire value of a trade. And it is worth being clear about what CLS is not: it is not a central counterparty. CLS does not become the buyer and seller of every trade. The original trade remains between the two banks. CLS is the settlement layer that makes sure neither side is left waiting in the dark.

Netting: making settlement smaller and cheaper

In the real world, a large bank does not settle one trade a day. It settles thousands. If every currency payment moved in full, the amount of money sloshing around the system would be enormous. CLS shrinks that burden through multilateral netting.

Each settlement member holds a single multicurrency account at CLS. Before settlement day, CLS works out, for each member and each currency, what it owes and what it is owed. Then it nets those positions across all members, so each member only funds the amount left after everything has cancelled out. If you owe someone 100 euros and they owe you 80, it makes little sense to move both full amounts when 20 euros settles the difference. CLS does that logic at global scale.

The efficiency is striking. CLS says its netting reduces funding requirements by more than 96%. It even has a tool called in/out swaps that can shrink funding needs further, sometimes to less than 1% of the total gross settlement value. That saves members a great deal of cash—and in moments of stress, available cash is the most precious thing a bank can have.

The five-hour window: when the world’s payment systems line up

Simultaneous settlement sounds neat, but how does it actually happen? Every currency that CLS settles is ultimately paid through its home country’s real-time gross settlement system, or RTGS—the central bank system that moves money between banks in real time. For the two legs of an FX trade to settle together, all the relevant RTGS systems need to be open at the same time.

This is why CLS runs on a five-hour window every settlement day. During that window, the real-time systems in its 18 currencies overlap, and members pay in the currency they owe according to a schedule set by CLS. Once the payments are confirmed, CLS settles the matched instructions by debiting and crediting member accounts. The transfers are final and irrevocable.

Members begin the day with zero balances and end with zero balances; CLS itself does too. It is not a giant pool of money parked overnight. It is a choreographed daily meeting of currencies. To create that overlap, some countries had to extend their payment system hours—Australia, Canada and Japan among them.

This also explains why currency settlement has deadlines. CLS is built for trades that settle one or two days after the trade date; same-day trades are not currently eligible. Instructions must be submitted by a cutoff time—for next-day settlement, the cutoff can be as early as midnight Central European Time. So a currency deal made in the morning may not settle by lunchtime. The plumbing works on a schedule.

What CLS cannot do

PvP eliminates settlement risk for the trades it can handle, but it is not a cure for every risk. If one side defaults before settlement, the other may still face replacement cost risk—the cost of replacing the deal at a worse market price. And CLS itself can use standby credit lines with major banks to manage a member’s failure, but those lines are finite while the value of trades is not, so liquidity risk is reduced rather than erased.

There are also limits to what can be routed through CLS. It settles 18 major currencies, and not every counterparty has direct or indirect access. In April 2025, according to the BIS Triennial Survey, more than $14 trillion of gross FX obligations settled on an average day. About 36%, a little over $5 trillion, settled via PvP, eliminating settlement risk. A further 54% used methods that reduce but do not remove it. The remaining 10%—more than $1.4 trillion a day—settled on a gross bilateral basis, meaning the two parties paid each other directly with no PvP protection.

CLS is therefore not the whole story, but it is a big reason the story is safer than it was fifty years ago. The next time a headline mentions trillions of dollars moving in currency markets, you can picture the quiet five-hour window where the world’s payments meet, match and settle together—or not at all.