What T+1 Settlement Means for Your Currency Trades

A shorter layover, same distance

Imagine landing in a busy airport with a connection to catch. Under the old rules, you had a comfortable two-hour layover. Under the new rules, you have forty-five minutes, you're on the wrong side of the terminal, and your bags still need to move. Nothing about the journey changed. The time to make it did.

That's roughly what's happening to securities settlement. For years, when you bought a stock or bond, the trade and the payment for it were finalised two business days after the trade date — a cycle known as T+2. In May 2024, the United States, Canada, Mexico and Argentina moved to T+1: settlement one business day after the trade. The UK, the EU and Switzerland have now set a common go-live date of 11 October 2027 for their own shift to T+1.

The idea is straightforward. The less time between agreeing a trade and settling it, the less time for something to go wrong — a counterparty to fail, prices to move, or collateral to sit tied up. The UK's financial regulator, the FCA, says the change aims to make markets more efficient and reduce risk, and that firms should already have project plans and budgets in place, with system changes tested by the end of 2026.

But here's the part that rarely makes headlines: shortening the securities cycle doesn't just affect stocks and bonds. It squeezes the currency trades that pay for them.

Why currency is the hidden passenger

If you're a fund in Tokyo buying US equities, or a European manager buying UK gilts, you don't just need the security. You need the right currency in the right place at the right moment. That means an FX trade — a foreign exchange transaction — usually running alongside the securities trade.

Historically, many FX trades settle on a T+2 rhythm of their own. So when securities settle at T+2 and currency settles at T+2, the two can travel together comfortably. When securities jump to T+1 and currency doesn't, the pairing gets awkward. The currency has to arrive earlier, which means the FX trade has to be executed earlier — often on the same day the securities trade is struck.

Industry analysis of the US transition described the practical effect bluntly. From the close of North American equity markets, there was roughly one hour to trade the FX and about one hour to submit the details for settlement through CLS, the main industry service that settles both sides of a currency trade simultaneously. One hour is not a lot of time to notice a problem, let alone fix one.

The FCA has also weighed in on the broader machinery. It expects firms to implement appropriate automation, which can increase processing capacity and resilience during busy or stressed markets. The message across the industry is consistent: manual steps and late fixes are the enemy here.

The FX fixing window, explained

A quick word on the "fixing." In currency markets, a fixing is a reference rate — a benchmark price calculated at a set time each day, widely used to value portfolios and to execute orders at a known rate. Because fixings happen at specific moments, trading activity tends to cluster around them. If T+1 pushes more currency trading into a narrower slice of the day, some of that activity may bunch up near those windows, and near market close.

That's a plausible operational consequence, not a certainty. Trading volume may simply shift. Banks have reportedly discussed extending staffing on sales and trading desks to cover the later hours. Liquidity, in other words, may not vanish — but it may move house.

It's worth being honest about what we don't know. How much liquidity actually migrates, and whether pricing changes as a result, will only become clear once markets adapt. Anyone who tells you the exact answer today is guessing.

Herstatt, and why settlement risk has a name

None of this is abstract. On 26 June 1974, German authorities ordered Bankhaus Herstatt into liquidation at 3.30pm Frankfurt time. Its New York correspondent suspended outgoing dollar payments. Counterparties who had already paid out Deutsche marks that morning received nothing in return. Cross-border payments seized up; markets lost trust; the turmoil eased only after major central banks signalled they would provide liquidity.

That episode gave FX settlement risk its nickname: Herstatt risk. It's the risk that you deliver the currency you sold and don't receive the currency you bought. A single failure of that kind can ripple, because a missed payment makes the next firm cautious, and caution spreads.

The response took decades. The Basel Committee on Banking Supervision was established at the end of 1974. CLS Bank launched in 2002, offering payment-versus-payment settlement — a mechanism where the final payment of one currency happens if, and only if, the final payment of the other does. According to the BIS 2025 Triennial Survey, just over $5 trillion a day, or 36% of average daily settlement in April 2025, went through PvP systems. A further $7.6 trillion, or 54%, used methods like pre-settlement netting, which reduce but don't eliminate the risk. And more than $1.4 trillion — about 10% — settled gross bilateral, fully exposed.

Progress, yes. Perfection, no. The survey notes that a quarter of that gross bilateral amount was actually eligible for PvP settlement and simply didn't use it, sometimes because trades missed cut-off times.

Where shorter cycles could pinch

This is where the two stories meet. The BIS survey flags a specific concern: PvP systems generally handle T+1 or T+2 settlement, with fixed cut-off times. Same-day, T+0 trades currently can't go through PvP. If more jurisdictions move to T+1 for securities, the need for same-day FX swaps to fund cross-border purchases may increase — and so, potentially, may the volume settling on a fully exposed basis.

The survey also notes that shorter cycles leave less time to fix confirmation or settlement problems. Without more automation and straight-through processing, that could mean more failed FX trades, and knock-on failures in the securities they were meant to fund.

Regulators are watching this closely. The Bank for International Settlements survey found settlement fails were limited — 0.01% of gross obligations in April 2025 — but noted that continued monitoring matters precisely because cycles are shortening.

What practitioners are actually doing

Several themes recur across industry guidance. Automate allocations and confirmations so they're done on trade date, not the next morning. Make standing settlement instructions accurate and exchanged early — poor data quality is repeatedly named as a leading cause of fails. Forecast funding needs intraday rather than at day's end. And test, early and often: five industry-wide testing windows are planned across 2027 for the UK, EU and Switzerland.

One industry body has proposed a "gating event" — a mechanism that would release flagged settlement instructions for processing at a set time in late morning, preserving the netting efficiencies that repos and financing transactions depend on. It's a technical fix to a technical problem, and a good illustration of how much plumbing sits beneath a settlement cycle.

The honest bottom line

T+1 is a genuine efficiency gain and a genuine operational challenge, and those two things are not in conflict. Less exposure time is good. Less recovery time is harder. For ordinary investors, the practical effect is likely to be invisible most days — but it matters beneath the surface, because it shapes how smoothly the machinery that holds your holdings actually runs.

The details also differ by jurisdiction. The UK, EU and Switzerland have aligned their dates, but implementation rules, exemptions and market practices vary, and some instruments — like securities financing transactions — sit outside the requirement while still needing to work alongside it. If you're making decisions that depend on these specifics, check the rules that apply where you are.

And spare a thought for the operations teams. They've spent years being told to think about what time it is in New York. Now they have to think about it faster.