Guide · Updated September 17, 2026
How to eliminate nostro prefunding with stablecoins
Payment companies prefund nostro accounts because bank settlement is slow. Stablecoin settlement closes the gap to minutes, so corridors run on per-trade funding instead of parked capital.
What prefunding actually costs
Prefunding is capital parked in payout markets ahead of demand. The mechanics: estimate what each corridor will pay out, wire that amount into local nostro accounts before it is needed, and top the balances up as they drain. The number that matters is how much sits idle across all corridors at once.
A worked example: a PSP paying out in six corridors, averaging 250,000 USD per corridor per day, holding a three-day buffer against settlement lag and peak days.
| Corridors | 6 |
| Average daily payout per corridor | $250,000 |
| Buffer held per corridor | 3 days |
| Capital parked at all times | $4,500,000 |
| Annual carry cost at 8% | $360,000 |
That 4.5 million USD is working capital producing nothing. At an 8 percent cost of capital, holding it costs 360,000 USD a year before anything moves, and the number scales linearly: double the corridors or the volumes and the parked capital doubles with it. Carry is only the visible cost. Non-dollar balances sit exposed to local currency moves, buffers are sized for peak days rather than average ones, and treasury time goes into forecasting and rebalancing them every week.
The industry-level version of this number is large. Oliver Wyman and J.P. Morgan estimate that global corporates move about 23.5 trillion USD across borders each year and pay more than 120 billion USD in transaction costs, a figure that excludes the hidden cost of trapped liquidity and delayed settlement (Oliver Wyman, 2021).
Why corridors trap capital
Three properties of bank settlement make the parked capital mandatory rather than optional.
Settlement lag. Cross-border payments on correspondent rails settle in one to five business days. T+2 is the spot FX convention, missing a cut-off adds a day, and weekends and holidays do not count. Money sent Thursday evening may not be usable until Tuesday. Payouts cannot wait for it, so a buffer pays them in the meantime.
No netting between corridors. Each corridor holds its own currency in its own account. A surplus in Mexican pesos cannot cover a shortfall in Brazilian reais. Buffers stack per corridor, so every new market adds a new balance.
Buffers are sized for the worst day. A buffer that covers the average day fails on the month-end spike, so treasury sizes for peaks plus a margin. Most of that capital sits unused for most of the year.
The banking side is shrinking too. BIS data shows the number of active correspondent banking relationships fell about 25 percent between 2011 and 2020 even as payment values grew (BIS CPMI, 2021). Fewer relationships mean longer chains and slower settlement in exactly the emerging market corridors where payout growth is fastest.
How stablecoin settlement replaces prefunding
The stablecoin model changes when money needs to be in the destination: minutes ahead instead of days ahead. The shape of a corridor trade:
- 1.Lock a rate. One wholesale FX rate for the full corridor, local fiat to local fiat. The rate you see is the rate you settle at; the fee is billed separately.
- 2.Fund the specific trade. Send fiat to a local account or stablecoins to the address provided. This is per-trade funding: nothing parked, nothing estimated in advance.
- 3.The value crosses as stablecoins. USDC or USDT moves onchain in minutes, any hour, any day. No cut-off times and no correspondent chain in the middle.
- 4.Local fiat pays out. The off-ramp leg converts to the destination currency and pays the beneficiary account.
Because the cross-border leg finalizes in minutes, payouts are funded by the trades themselves. The three-day buffer exists to bridge a three-day settlement gap; a thirty-minute gap does not need one.
Codex FX clears more than 1 billion USD a month on this model for payment companies, with the fastest trades settling in under 30 minutes and most completing the same day, 24/7/365, across USD, EUR, GBP, MXN, and BRL alongside USDC and USDT on nine blockchain networks, through a dashboard and API. For contrast: the G20's own roadmap targets 75 percent of cross-border wholesale payments credited within one hour of initiation by the end of 2027 (FSB targets, 2021). Stablecoin corridors clear that bar today.
Estimate your trapped capital
Put your own corridor numbers in. The calculator estimates the capital parked in prefunding and what holding it costs per year.
Capital parked in prefunding
$4,500,000
Annual carry cost
$360,000
Estimates only: carry cost before FX exposure on non-USD balances and treasury time. To price your actual corridors, book a demo.
When prefunding still makes sense
Stablecoin settlement does not remove every buffer for every business.
Instant payout SLAs. A promise of money in seconds, at any hour, still needs a local float in that market: even a thirty-minute settlement window is too slow for an instant SLA. What changes is the size, a buffer measured in hours of payouts instead of days.
Corridors without off-ramp coverage. Where no licensed provider converts stablecoins to the destination currency, bank rails remain the only route, with the prefunding they imply.
Jurisdiction constraints. Regulated businesses can settle over stablecoins where their licenses and their provider's coverage overlap. Codex FX onboards licensed businesses across its supported markets.
Very small corridors. Below a certain volume, the carry cost of a small buffer is cheaper than changing settlement infrastructure. The calculator above makes that comparison concrete.
Frequently asked questions
An account a bank or payment company holds at a bank in another country, in that country's currency, used to make local payments there. Prefunding is the practice of loading these accounts ahead of payout demand. See the full definition in the glossary.
A useful rule of thumb: corridors x average daily payout per corridor x buffer days. A PSP with six corridors at 250,000 USD a day and three-day buffers holds 4.5 million USD idle. The calculator on this page estimates your own number and its annual carry cost.
Yes, in most major jurisdictions, subject to your licenses and local rules. On Codex FX, KYB and compliance checks run up front, client funds sit in institutional custody, and AML screening runs on every trade, in line with MiCA and MSB standards. Book a demo to walk through what applies in your jurisdiction.
T+2 means two business days, and cut-off times, weekends, and holidays stretch it further, so money can take four calendar days to arrive. Stablecoin settlement runs 24/7: on Codex FX the fastest trades settle in under 30 minutes and most complete the same day.
No. You don't park a balance with us. Lock a rate, then fund that specific trade, either by sending fiat to a local Codex account or stablecoins to the address we provide.
See it on your corridors: a 15-minute demo maps the routes you run, shows live pricing, and walks through onboarding. Related reading: how to choose a stablecoin on/off-ramp provider and what stablecoin FX infrastructure is.