A stablecoin payment gateway lets an online store take payments and settle them in a dollar stablecoin such as USDC. A buyer can pay in USDC from their own wallet. Or, with a card on-ramp built in, a buyer pays by card, Apple Pay or Google Pay and the store still receives USDC. Either way the money lands in the merchant's wallet, per order, without a bank in the middle.
This guide covers how these gateways work, why most of them run on networks such as Polygon, what to check before you pick one, and how to record stablecoin income cleanly.
Why stores take stablecoins#
- Dollar value. A stablecoin is designed to track the US dollar. Circle, which issues USDC, says it holds a dollar of cash and cash-equivalent assets in reserve for every USDC in circulation.
- Per-order settlement. Each paid order can be its own transfer to your wallet, at any hour, instead of a batch payout days later.
- Your own wallet. Funds arrive at an address you control, not in a balance someone else can hold back.
- Buyers anywhere. A stablecoin transfer works the same from any country. With a card on-ramp, so does a card payment, subject to the provider's coverage.
How a stablecoin gateway works#
- Your server creates a checkout for the order: amount, currency, and where to send the buyer and the notification.
- The buyer pays on a hosted page, either by sending stablecoins or by card through an on-ramp provider that delivers stablecoins.
- The gateway watches the network until the payment for that checkout arrives and confirms, then compares it with the amount due.
- It settles to you by sending the payment minus its fee to your wallet, and sends your server a signed notification so the order can be marked paid.
With Caravel Pay, each payment arrives at a deposit address for that checkout and is forwarded to your payout wallet automatically, minus the 2% Caravel fee. There is no balance held for you and nothing to withdraw.
Two ways your buyers can pay#
| Buyer pays by card, Apple Pay or Google Pay | Buyer pays in crypto directly | |
|---|---|---|
| Buyer needs a wallet? | No | Yes, holding USDC, USDC.e or POL on Polygon |
| Extra cost to the buyer | The card provider's fee, shown before paying | A small Polygon network fee |
| You receive | USDC on Polygon, minus the 2% Caravel fee | The same token they sent, minus the 2% Caravel fee, never swapped |
| Wrong token or network | n/a | Can't be credited automatically; the checkout goes to review |
For most online stores the card path matters more, because most shoppers don't hold stablecoins. The direct path suits buyers who already do, and costs them less.
Why Polygon#
A stablecoin exists on many networks, and the network decides the speed and the transfer cost. Polygon PoS is a common choice for payments because transfers are cheap and quick to confirm, and because Circle issues USDC natively there. Circle's contract address list gives native Polygon USDC as 0x3c499c542cEF5E3811e1192ce70d8cC03d5c3359.
Polygon also has an older, bridged token called USDC.e, which Circle says it does not issue. Gateways and exchanges treat the two differently, so it's worth knowing which one you'll receive: see USDC vs USDC.e.
What to check before you choose a gateway#
| Question | Why it matters | Caravel Pay |
|---|---|---|
| Who holds the money, and for how long? | Balances held by a gateway can be frozen or delayed | Forwarded to your wallet automatically once confirmed; no held balance |
| What's the fee, all in? | Some gateways add network costs, swap spreads or per-method tiers | 2% Caravel fee; gas for your payout included |
| Is anything swapped? | A swap adds a spread and changes what you receive | Never: you get the token that was paid |
| What happens to short or late payments? | A loose tolerance can mark short payments as paid | underpaid and review statuses; the order goes on hold |
| Are notifications signed? | Unsigned callbacks can be forged | Every webhook is signed with HMAC-SHA256 and retried for 24 hours |
| Can you reconcile without a dashboard? | You need amounts and transaction hashes per order | Each checkout carries payout.amount, asset and tx_hash; GET /v1/checkouts lists them |
| Can buyers pay by card? | Most shoppers don't hold stablecoins | Card, Apple Pay and Google Pay through an on-ramp provider |
Keeping the books straight#
- Per paid order: record the order total in USD, the payout amount and token, and the transaction hash. The checkout object carries all of these.
- Separate tokens: if direct crypto buyers send USDC.e or POL, those payouts arrive in that token. Keep them in separate ledgers, or convert them yourself.
- Keep some POL in your wallet: Polygon network fees are paid in POL, so you'll need a little to move your USDC onward. Caravel Pay covers the gas for sending you the payout, not for what you do with it afterwards.
- Ask an accountant how stablecoin receipts are treated where you are. Being paid in USDC doesn't change your tax obligations.
Getting started with Caravel Pay#
There's no account and no sign-up form. On WooCommerce, install the plugin and save your wallet; see the WooCommerce guide. On any other platform, one call to POST /v1/connect returns your keys, and the quickstart covers the checkout and the webhook.
Frequently asked questions#
What is a stablecoin payment gateway?#
A service that creates checkouts for your orders, detects stablecoin payments on-chain, and settles them to your wallet with a signed notification to your store. Some also take card payments through an on-ramp provider and settle those in stablecoins too.
How do I accept USDC payments on my website?#
Use a gateway that supports USDC on your chosen network. With Caravel Pay: get keys with one API call (or the WooCommerce plugin), create a checkout per order, redirect the buyer, and mark the order paid when the checkout.paid webhook arrives.
Can buyers pay by card and I still get USDC?#
Yes. A card on-ramp provider sells the buyer USDC as part of the payment. You receive the order total minus the 2% Caravel fee, as USDC on Polygon, and the buyer pays the provider's fee.
Are stablecoin payments reversible?#
Payouts are final on-chain transfers, so there are no chargebacks to the merchant. If a buyer disputes a card payment, that's between the buyer, their bank and the card provider that sold the USDC. Refunds are sent by you, from your wallet.
Which stablecoins does Caravel Pay accept?#
Card payments arrive as USDC. Buyers paying directly can send USDC, USDC.e or POL on Polygon. Other tokens and networks go to review.
Sources#
- Circle: USDC on Polygon PoS (reserves, native USDC, bridged USDC.e not issued by Circle), checked 2026-11-09.
- Circle: USDC contract addresses (Polygon PoS native USDC), checked 2026-11-09.
- Caravel Pay docs: Payouts and fees, Checkouts, Checkout statuses, Webhooks.