Stablecoins for merchants: what converting to euros costs

A stablecoin is a digital token pegged to a currency: one USDC tracks the dollar, one EURC tracks the euro. With FiatFlex, accepting them costs nothing; the cost arrives when you convert to euros and send the money to your bank account, which is 1% FiatFlex commission, plus a flat bank fee of 0.30 USD per SEPA transfer, plus 0.50% of spread if the amount is in USDC, since EURC converts at par.

The rest of this article makes those three lines concrete: the maths on €100, the maths on €10, and the point where a stablecoin saves you nothing at all.

What a stablecoin is, plainly

An ordinary cryptocurrency changes value hour by hour. A stablecoin is built not to: the issuer holds reserves and commits to one token being worth one unit of the reference currency.

A customer who sends you 100 EURC sends you the equivalent of 100 euros, and 100 USDC is the equivalent of 100 dollars. You have not opened a position on a market: you have received an amount denominated in a currency you already understand.

The rest, the blockchain and the addresses, is plumbing you never touch.

Why USDC and EURC, and why on Solana

FiatFlex accepts two stablecoins, USDC and EURC, both issued by Circle, on a single network, Solana. Network fees there are low, which is what lets accepting a payment stay free for you.

Two tokens and one network is a choice. Adding networks mostly adds ways to send money to an address that will never receive it. One address, two tokens: your customer makes fewer mistakes, and so do you.

Accepting is free, converting is what costs

Three things cost you nothing: receiving stablecoins, holding a stablecoin balance, and withdrawing your card takings to your bank. There is no subscription, no signup fee and no hardware to buy.

One operation is billed: converting to euros and sending the SEPA transfer. It breaks down into three lines.

• 1% FiatFlex commission on the amount converted.
• 0.30 USD flat bank fee per SEPA transfer, whatever the amount. It is charged once per transfer, not per payment received, and the exact amount is shown to you before you confirm the conversion.
• 0.50% of spread, only if you are converting USDC. EURC is at par, so no spread.

The word that matters is "flat". The 0.30 USD does not move with the amount, and that is the whole story of small tickets.

The maths on €100, then on €10

On €100 received in EURC and converted: €1.00 of commission, plus the flat bank fee of 0.30 USD, so €1.26 in total.

On the same €100 taken by card, our commission is 0.50% and Stripe bills its own fees to the merchant's own Stripe account: 1.4% + €0.20 with Tap to Pay, 1.5% + €0.25 on a payment link, for a consumer card issued in the European Economic Area. The total is €2.10 with Tap to Pay and €2.25 on a link.

Now the same exercise on a €10 ticket, converted on its own:

• in EURC: €0.10 of commission, plus the flat bank fee of 0.30 USD in full;
• in USDC: €0.10 of commission, €0.05 of spread, plus the same flat bank fee in full;
• by card, with Tap to Pay: €0.05 to us, €0.14 and €0.20 to Stripe, so €0.39.

Read those three lines together: on a €10 ticket converted on its own, a stablecoin is not cheaper than a contactless card payment. In EURC it is about the same; in USDC it is more expensive. The flat bank fee does not shrink with the amount, and on a €10 conversion no percentage commission can make that back.

The stablecoin regains the advantage in two common cases.

• The ticket is large. At €100, €1.26 against €2.10 or €2.25: the gap is clear, and it widens as the amount goes up.
• You group your conversions. Ten €10 takings in EURC converted in one operation is €100 converted, so €1.26 in total. The flat bank fee was charged once instead of ten times.

The rule fits in one sentence: convert in batches, not one payment at a time. The full schedule, cards included, is in our pricing.

USDC or EURC: where the 0.50% goes

The 0.50% spread applies to USDC only, because the amount has to move from dollars to euros. EURC is already in euros and converts at par. On €100 that is €0.50 on one side and nothing on the other.

If you invoice in euros and your customers can pay in EURC, ask for EURC. If your customers think in dollars, accept USDC knowing what the conversion costs on top.

Who is regulated, and where the money sits

This part has to be precise, because it is where marketing language usually slips.

FiatFlex is not a bank, not a payment institution and not an electronic money institution. The regulated partners are Stripe, for card payments, and Bridge, for stablecoins and the SEPA transfer.

The Solana wallet we open for your account is custody: FiatFlex holds those funds until you ask for a conversion or a withdrawal. It is custody in the plain sense, not self-custody, and we will never write it up as anything else. The full path the money takes is described in cards and stablecoins, two ways to get paid.

A stablecoin payment does not run over the card networks, so there is no dispute procedure, and our card dispute fees, €20 per dispute received and another €20 if you contest it, the second returned if you win, do not apply to it. The trade-off is real: a transfer sent to the wrong address does not come back.

What we do not write

We publish no timings, for any step: not for a payment arriving, not for the conversion, not for the SEPA transfer. Our banking partner has confirmed none to us, so we advertise none.

The schedule is public and applies as it stands, with no quote to request.

We are launching in France: what is described here, stablecoins and cards alike, is for merchants in France, and Tap to Pay on iPhone is available there at launch.

Frequently asked questions

Do I need to hold cryptocurrency to accept stablecoins?

No. You can convert every payment to euros and never keep a balance. You can also keep part of it: you decide, operation by operation.

USDC or EURC?

EURC if you invoice in euros, since it converts at par without the 0.50% spread. USDC if your customers think in dollars. The detail is in USDC or EURC, which to choose.

Is a stablecoin cheaper than a card?

It depends on the ticket and on how you convert. On €100: €1.26 in EURC against €2.10 with Tap to Pay and €2.25 on a link. On €10 converted on its own the flat bank fee of 0.30 USD lands in full, so EURC is much the same as the €0.39 of a Tap to Pay, and USDC, with its spread, is more expensive.

Is FiatFlex a bank?

No. The regulated partners are Stripe and Bridge, and the wallet we operate is custody.

Where can I see the schedule and try the app?

On the pricing section, and by downloading the app.