Off-ramp: Withdraw stablecoin to a US bank account

Goal

Withdraw USDC from a customer’s Bastion account to their own US bank account in USD, using an off-ramp conversion. Scope: USDC to USD, wire only, first-party only (the customer withdraws to a bank account they own). To pay out to a bank account outside the United States, or to a third party, see Withdraw stablecoin to an international bank account.

Key entities

Entity	Description
Your platform	The product integrating Bastion’s APIs
Customer	An individual or business your platform has onboarded (KYC/KYB-verified), with a funded account and a linked bank account
Identity	The customer’s record in Bastion
Account	A Bastion account linked to the identity that holds balances and transacts
Conversion	A value change between assets (e.g. USDC on Solana to USD in a bank account) via `POST /v2/conversions`
Payment instructions	Bank account details (wire instructions) used to pay USD out to the customer’s bank

Flow overview

The steps to withdraw funds from a stablecoin balance to a US bank account are:

Confirm identity, account, and balance
Register payment instructions
Submit the conversion
Track status
Show updated balance

Prerequisites

Customer has a verified identity (KYC or KYB) with fiat_operations_enabled = true
Customer has an on-chain account with a USDC balance on a supported chain
You have an API key and a registered webhook
The customer’s principal address is not in New York. See Jurisdiction overview

US off-ramps are supported on Ethereum, Solana, and Base. See Supported chains and assets.

Step 1 – Confirm identity, account, and balance

Before allowing a withdrawal, confirm the customer can transact and has sufficient balance. Get the identity

GET /v2/identities/{identity_id}
Authorization: Bearer YOUR_API_KEY

Verify these fields:

Field	Required Value
`status`	`ACTIVE`
`fiat_operations_enabled`	`true`

Get balances

GET /v2/accounts/{account_id}/balances
Authorization: Bearer YOUR_API_KEY

{
  "balances": [
    {
      "symbol": "USDC",
      "total": "750000000",
      "available": "750000000",
      "decimals": 6
    }
  ]
}

Balances are returned in base units. Divide by 10 ^ decimals to get the decimal amount: 750000000 with decimals: 6 is 750.000000 USDC. Conversions take decimal strings, not base units. Verify available covers the withdrawal amount. Fees are deducted from that amount rather than added to it, so the customer’s total debit equals the amount you submit.

Step 2 – Register payment instructions

Register the customer’s bank account as payment instructions. The returned payment_instructions_id is reusable across withdrawals to the same bank account. Request

POST /v2/identities/{identity_id}/payment-instructions
Content-Type: application/json
Authorization: Bearer YOUR_API_KEY

{
  "request_id": "a3b1c4d2-e5f6-4a89-b0c1-d2e3f4a5b6c7",
  "payment_method": "WIRE",
  "country": "US",
  "fiat_currency_symbol": "USD",
  "account_name": "John's Chase Account",
  "beneficiary_type": "FIRST_PARTY",
  "bank_account_details": {
    "name": "Chase",
    "wire_details": {
      "account_number": "123321",
      "routing_number": "321123",
      "type": "CHECKING",
      "address": {
        "street_line_1": "270 Park Ave",
        "city": "New York",
        "postal_code": "10017",
        "country": "US",
        "region_code": "NY"
      }
    }
  },
  "recipient": {
    "individual": {
      "first_name": "John",
      "last_name": "Doe",
      "email": "john.doe@example.com",
      "address": {
        "street_line_1": "100 Biscayne Blvd",
        "city": "Miami",
        "postal_code": "33132",
        "country": "US",
        "region_code": "FL"
      }
    }
  }
}

Field notes

Field	Description
`request_id`	UUID idempotency key. Generate a unique UUID for each registration, and reuse the same `request_id` on retries to avoid creating duplicate payment instructions
`account_name`	User-facing label for the saved payment method (e.g. “John’s Chase Account”)
`beneficiary_type`	`FIRST_PARTY`. US off-ramps pay out only to a bank account the customer owns
`bank_account_details.name`	Required. The bank’s legal name (e.g. “Chase”)
`wire_details.type`	`CHECKING` or `SAVINGS`
`wire_details.address`	The bank’s address, not the customer’s
`recipient.individual.first_name`	Recipient’s first name
`recipient.individual.middle_name`	Optional
`recipient.individual.last_name`	Recipient’s last name
`recipient.individual.email`	Required on all registrations
`recipient.individual.address`	The recipient’s address, not the bank’s

Response

{
  "id": "3Cb0rR32xNl2GAHFjJc4EHEcdPw",
  "payment_method": "WIRE",
  "country": "US",
  "fiat_currency_symbol": "USD",
  "account_name": "John's Chase Account",
  "beneficiary_type": "FIRST_PARTY",
  "bank_account_details": {
    "name": "Chase",
    "wire_details": {
      "account_number": "123321",
      "routing_number": "321123",
      "type": "CHECKING",
      "address": {
        "street_line_1": "270 Park Ave",
        "city": "New York",
        "postal_code": "10017",
        "country": "US",
        "region_code": "NY"
      }
    }
  },
  "recipient": {
    "individual": {
      "first_name": "John",
      "last_name": "Doe",
      "email": "john.doe@example.com",
      "address": {
        "street_line_1": "100 Biscayne Blvd",
        "city": "Miami",
        "postal_code": "33132",
        "country": "US",
        "region_code": "FL"
      }
    }
  }
}

Store the id as payment_instructions_id so you can reference it on the conversion request and reuse it for future withdrawals to this bank account.

Step 3 – Submit the conversion

Submit a conversion that debits USDC from the customer’s account and sends USD to their bank. Request

POST /v2/conversions
Content-Type: application/json
Authorization: Bearer YOUR_API_KEY

{
  "request_id": "903c9e51-51af-4597-9174-0a93ca80dbac",
  "amount": "500.00",
  "account_id": "36hv3yZpsHt7pwgBZom5SXgURYz",
  "payment_purpose": "PERSONAL_REMITTANCE",
  "source": {
    "currency": "USDC",
    "payment_method": "BLOCKCHAIN",
    "chain": "ETHEREUM_MAINNET"
  },
  "destination": {
    "currency": "USD",
    "payment_method": "WIRE",
    "payment_instructions_id": "3Cb0rR32xNl2GAHFjJc4EHEcdPw"
  }
}

payment_purpose is required and must describe the nature of the payout. See the API reference for valid values. destination.payment_method and destination.currency must match the payment_method and fiat_currency_symbol on the registered payment instructions. Response - INITIATED

{
  "id": "3GTrcGxI4dvxsVzWxIRPOpQp3S1",
  "request_id": "903c9e51-51af-4597-9174-0a93ca80dbac",
  "account_id": "36hv3yZpsHt7pwgBZom5SXgURYz",
  "amount": "500.00",
  "type": "OFF_RAMP",
  "status": "INITIATED",
  "payment_purpose": "PERSONAL_REMITTANCE",
  "source": {
    "amount": "500.00",
    "currency": "USDC",
    "payment_method": "BLOCKCHAIN",
    "chain": "ETHEREUM_MAINNET"
  },
  "destination": {
    "amount": "486.00",
    "currency": "USD",
    "payment_method": "WIRE",
    "payment_instructions_id": "3Cb0rR32xNl2GAHFjJc4EHEcdPw"
  },
  "exchange_rate": "1.0",
  "fee_model": "DEDUCTED",
  "fees_total": "14.00",
  "fees_total_currency": "USDC",
  "fees": [
    {
      "amount": "14.00",
      "currency": "USDC",
      "type": "PLATFORM"
    }
  ],
  "created_at": "2026-04-19T15:00:00Z",
  "updated_at": "2026-04-19T15:00:00Z",
  "completed_at": ""
}

The PLATFORM fee is the wire processing cost. It is deducted from amount before payout, so destination.amount is amount minus fees_total.

Tip: use a unique request_id (UUID) as an idempotency key, and reuse the same request_id on retries. The payment_instructions_id can be reused across withdrawals to the same bank account.

Step 4 – Track conversion status

Track the conversion via webhooks (recommended) or polling until it reaches a terminal state.

Option A: Webhooks

Configure a webhook endpoint in the Bastion dashboard to receive conversion events. Each event carries the conversion object in data, using the same shape as the submit response.

{
  "id": "3GuXD1oNPTfqc9sIsbmbnqr6rx5",
  "type": "conversion_notification_update",
  "data": {
    "id": "3GTrcGxI4dvxsVzWxIRPOpQp3S1",
    "request_id": "903c9e51-51af-4597-9174-0a93ca80dbac",
    "account_id": "36hv3yZpsHt7pwgBZom5SXgURYz",
    "amount": "500.00",
    "type": "OFF_RAMP",
    "status": "COMPLETED",
    "payment_purpose": "PERSONAL_REMITTANCE",
    "source": {
      "amount": "500.00",
      "currency": "USDC",
      "payment_method": "BLOCKCHAIN",
      "chain": "ETHEREUM_MAINNET"
    },
    "destination": {
      "amount": "486.00",
      "currency": "USD",
      "payment_method": "WIRE",
      "payment_instructions_id": "3Cb0rR32xNl2GAHFjJc4EHEcdPw"
    },
    "exchange_rate": "1.0",
    "fee_model": "DEDUCTED",
    "fees_total": "14.00",
    "fees_total_currency": "USDC",
    "fees": [
      {
        "amount": "14.00",
        "currency": "USDC",
        "type": "PLATFORM"
      }
    ],
    "created_at": "2026-04-19T15:00:00Z",
    "updated_at": "2026-04-19T15:45:00Z",
    "completed_at": "2026-04-19T15:45:00Z"
  }
}

The top-level id is unique per delivery. The stable conversion ID is data.id. See Conversion notifications for the full schema. On FAILED and RETURNED, the event carries failure_reason with a human-readable description of what went wrong. Log it, and use it to decide between prompting the customer to correct bank details and routing to support. Do not display it to the customer verbatim. Status progression INITIATED to PROCESSING to PAYOUT_INITIATED to PAYOUT_IN_PROGRESS to COMPLETED Handle statuses:

Status	Action
`INITIATED`, `PROCESSING`	Show a processing indicator; do not allow double-spend
`PAYOUT_INITIATED`, `PAYOUT_IN_PROGRESS`	Show “sending to your bank”; update the USDC balance
`COMPLETED`	Mark the withdrawal complete, refresh balances, and show it as settled
`FAILED`	Show an error, allow retry, or direct to support. Read `failure_reason`
`RETURNED`	The receiving bank rejected the payout. Prompt the customer to verify their bank details. Read `failure_reason`

For canonical status definitions and recovery guidance, see Stablecoin and fiat conversions.

Webhook reliability: failed deliveries are retried with exponential backoff (15 s base interval, 10 min max). Deduplicate using data.id and data.status. If no webhook arrives within a reasonable window, poll GET /v2/conversions/{conversion_id}.

Option B: Polling

Poll GET /v2/conversions/{conversion_id} as a fallback. Use the returned status and fee breakdown to update your UI.

Step 5 – Show updated balance

After the conversion completes, refresh balances and show the withdrawal in your history.

GET /v2/accounts/{account_id}/balances
Authorization: Bearer YOUR_API_KEY

UI recommendations:

Decrease the visible USDC balance by the amount submitted, which includes fees
Display the amount, the asset (USDC), the USD delivered, and the status
Show the destination with masked bank account details

Implementation notes

Recommendation	Details
Fees are deducted, not added	`fee_model` returns `DEDUCTED`. The `PLATFORM` fee comes out of the amount you submit, so the recipient receives less than the amount. Developer fees are not available on US payouts
Check balance first	Verify `available` covers the withdrawal before submitting, and handle insufficient funds gracefully
No minimum withdrawal	Wire has no network minimum, and Bastion does not add one. Because the fee is deducted from the amount submitted, the practical floor is any amount that exceeds the fee
Convert base units carefully	Balances are returned in base units; conversions take decimal strings
Use idempotent request IDs	Provide a unique `request_id` per conversion and per payment instruction registration. Reuse it on retries
Handle failures clearly	Treat `FAILED` and `RETURNED` as errors requiring customer messaging and potential manual review. Both carry `failure_reason`
Mirror in your database	Store `identity_id`, `account_id`, and `payment_instructions_id` alongside your internal user records so webhooks route to the right customer
Reuse payment instructions	`payment_instructions_id` is reusable across withdrawals to the same bank account
Be explicit about ownership	Make clear in your UI that withdrawals go to the customer’s own bank account

Getting Started

Concepts

Quickstarts

Compliance

Security

Bastion Dashboard

LLMs and MCP Server

Off-ramp: Withdraw stablecoin to a US bank account

Goal

Key entities

Flow overview

Prerequisites

Step 1 – Confirm identity, account, and balance

Step 2 – Register payment instructions

Step 3 – Submit the conversion

Step 4 – Track conversion status

Option A: Webhooks

Option B: Polling

Step 5 – Show updated balance

Implementation notes

What’s next

​Goal

​Key entities

​Flow overview

​Prerequisites

​Step 1 – Confirm identity, account, and balance

​Step 2 – Register payment instructions

​Step 3 – Submit the conversion

​Step 4 – Track conversion status

​Option A: Webhooks

​Option B: Polling

​Step 5 – Show updated balance

​Implementation notes

​What’s next

Goal

Key entities

Flow overview

Prerequisites

Step 1 – Confirm identity, account, and balance

Step 2 – Register payment instructions

Step 3 – Submit the conversion

Step 4 – Track conversion status

Option A: Webhooks

Option B: Polling

Step 5 – Show updated balance

Implementation notes

What’s next