How to Compare Stablecoin Conversion Quotes: Spreads, Fees, and Locked Rates

If your business moves between fiat and stablecoins, or between USDT and USDC, you will collect quotes from more than one provider. They rarely line up, because each provider builds its price differently.

This guide explains what a quote contains, how to compare ramp and swap quotes, and how to check that the rate you accept is the rate you settle at.

What Is a Stablecoin Conversion Quote?

A stablecoin conversion quote is the price a provider offers to exchange one currency for another, such as USD for USDC, USDT for EUR, or USDT for USDC. It starts from a market reference rate. The provider adds a spread, which is the gap between that reference and the price you get. Some providers also charge a separate fee. A quote is either indicative, meaning the price can still change, or firm, meaning the provider will trade at that price for a set time.

The number that decides the comparison is the all-in rate. It tells you what you receive for what you send, after the spread and any fees. Two quotes with the same headline rate can give different all-in rates.

How to Work Out the All-In Cost

Work out each quote's all-in cost in basis points against the same reference rate. A basis point (bp) is 0.01%, so 25 bps on $1 million is $2,500. Compare what the quote gives you with what the reference rate would give you, then add any fee charged outside the rate.

Some providers show their fee separately and others build it into the rate, so only the all-in cost compares them fairly.

Spreads also differ widely by market. Borderless.xyz tracked 260 payment corridors in 108 countries in the second quarter of 2026. It measured the gap between what providers charged to buy stablecoins and what they paid to sell them. The median gap was 6.1 bps in Asia, 89.0 bps in Latin America, and 512.8 bps in Africa.

Provider choice matters too. In the same report, a business using the median provider paid 23.3 bps more than the best available route. That is about $2,330 on every $1 million.

Indicative vs Firm Quotes

An indicative quote shows where the price is now, and it can change before your trade executes. A firm quote is a price the provider commits to for a set window once you confirm.

Exchange order books work like indicative quotes. You see a price, but a large order fills at several prices as it works through the book. Many retail on-ramps also show an indicative rate and apply their markup when the trade executes.

For a firm quote, ask how long the rate holds, whether the provider can reject or requote after you confirm, and what happens if you fund late. On the Codex FX stablecoin on/off-ramp, rates refresh every 15 seconds. The rate you lock is confirmed on the order before anything executes. You then have up to 12 hours to fund and settle at that rate, and quotes left unsettled void automatically.

If you're comparing providers for regular conversions, book a demo with Codex FX to see live rates for your corridors.

How to Compare On/Off-Ramp Quotes

Request every on/off-ramp quote for the same amount at the same time, then compare the all-in rates.

1. Agree the reference rate. A quote stated in basis points only means something next to its reference. Ask whether it is measured against an interbank mid-market rate, an exchange price, or 1:1.

2. Quote your real size. Prices change with size. Ask for the amount you will actually trade, not a small test amount.

3. Count the costs outside the rate. Bank charges on the fiat leg, network fees, and exchange withdrawal fees often sit outside the quote. Add them before you compare.

4. Check settlement and funding. A cheaper quote can cost more if it settles days later or needs prefunding, a balance held with the provider in advance. Both tie up capital.

5. Compare more than once. The cheapest provider changes. In Borderless.xyz's Q2 data, the cheapest provider of USDT for Brazilian reals changed 34 times in 88 days.

For the wider decision, see our guide to choosing a stablecoin on/off-ramp provider.

How to Compare USDT and USDC Swap Quotes

Compare a USDT and USDC swap quote with 1:1 and with the market price at the same moment, then add any fees and network costs. The market price is rarely exactly 1:1. Over the year to October 25, 2026, Binance's USDC/USDT market closed 2 bps or more from 1:1 on about two days in three. It closed 10 bps or more away on about one day in ten.

Size moves the price too. On the morning of October 26, 2026, buying $1 million of USDC with USDT on Binance's order book cost about 13 bps against 1:1. Buying $5 million cost about 23 bps, because the order reached deeper into the book.

On an exchange, you pay the market price plus any trading and withdrawal fees. Onchain, you pay the market spread plus gas and slippage. If you offer swaps to your own customers, Codex Par quotes exactly 1:1 in both directions and executes within a defined settlement window, 24/7/365. Your customers pay no fee and see no spread. Your cost as the operator is volume dependent, either billed per transaction or invoiced separately. Our guide to swapping USDT and USDC at scale covers each route in detail.

How Codex FX Prices Conversions

Codex FX is a stablecoin-native FX platform for payment companies and cross-border businesses. We clear more than $1 billion in volume every month. On the on/off-ramp, you trade on one all-in wholesale rate, locked when you confirm the order. Our fee is included in that rate and scales with your volume, so the rate you see is the rate you settle at. You can trade in the dashboard or through the API.

• Wholesale OTC pricing. Live two-way rates at institutional levels, refreshed every 15 seconds. You lock the exact rate before anything executes.
• USDC and USDT, every direction. Fiat to stablecoin, stablecoin to fiat, and stablecoin-to-stablecoin swaps without losing margin to poor execution.
• Same-day settlement. The fastest trades settle in under 30 minutes, and most complete the same day. We run 24/7/365.
• No prefunding. You fund each trade after you lock its rate, with no balance held with us in advance.
• Compliance built in. Onchain and offchain AML controls on every transaction, institutional custody, and KYB designed to take days, not months.

Book a demo with Codex FX to map your corridors and see live rates at your volume.

Frequently Asked Questions

What is a good spread for converting stablecoins?

It depends on the market and the size of your trade. In Borderless.xyz's Q2 2026 data, the median buy-sell spread ran from 6.1 bps in Asia to 512.8 bps in Africa. Compare quotes for your own corridors and amounts.

What is the difference between a firm and an indicative quote?

A firm quote is a price the provider commits to for a set window after you confirm. An indicative quote can change before your trade executes, so the price you get may differ from the price you saw.

Why don't USDT and USDC always trade at 1:1?

Both are designed to hold the value of one US dollar, but they trade against each other on open markets. Supply and demand move that price by a few basis points on most days. Over the past year, Binance's USDC/USDT market closed a median of 4 bps from 1:1.

How does Codex FX help?

Codex FX quotes on/off-ramp conversions at one all-in wholesale rate, locked when you confirm. Our fee is included in that rate and scales with your volume. For swaps between USDT and USDC, Codex Par quotes exactly 1:1, and your cost as the operator is volume dependent, either billed per transaction or invoiced separately.

To compare our rates with your current provider, book a demo with Codex FX.