> ## Documentation Index
> Fetch the complete documentation index at: https://docs.mercurjs.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Upsert Payment Details

> Create or update a seller's bank payment details.

Creates the seller's payment details if none exist, otherwise updates them.

## Path parameters

<ParamField path="id" type="string" required>The seller's ID.</ParamField>

## Query parameters

<ParamField query="fields" type="string">Comma-separated list of fields to include, prefix with `+`/`-` to add or remove from defaults.</ParamField>

## Body parameters

<ParamField body="country_code" type="string">Two-letter ISO country code of the bank account.</ParamField>
<ParamField body="holder_name" type="string">Name of the account holder.</ParamField>
<ParamField body="bank_name" type="string">Name of the bank.</ParamField>
<ParamField body="iban" type="string">IBAN of the account.</ParamField>
<ParamField body="bic" type="string">BIC / SWIFT code.</ParamField>
<ParamField body="routing_number" type="string">Routing number for US accounts.</ParamField>
<ParamField body="account_number" type="string">Account number.</ParamField>
<ParamField body="additional_data" type="object">Extra data passed to workflow hooks.</ParamField>

## Response

<ResponseField name="seller" type="object">
  <Expandable title="properties">
    <ResponseField name="id" type="string">The seller's ID.</ResponseField>

    <ResponseField name="payment_details" type="object">
      <Expandable title="properties">
        <ResponseField name="country_code" type="string">Two-letter ISO country code of the bank account.</ResponseField>
        <ResponseField name="holder_name" type="string">Name of the account holder.</ResponseField>
        <ResponseField name="bank_name" type="string">Name of the bank.</ResponseField>
        <ResponseField name="iban" type="string">IBAN of the account.</ResponseField>
        <ResponseField name="bic" type="string">BIC / SWIFT code.</ResponseField>
      </Expandable>
    </ResponseField>

    <ResponseField name="updated_at" type="string">Last update timestamp.</ResponseField>
  </Expandable>
</ResponseField>

<RequestExample>
  ```bash cURL theme={null}
  curl -X POST 'http://localhost:9000/admin/sellers/sel_01HXYZABCDEF/payment-details' \
    -H 'Authorization: Bearer <token>' \
    -H 'Content-Type: application/json' \
    -d '{
      "country_code": "de",
      "holder_name": "Acme GmbH",
      "iban": "DE89370400440532013000",
      "bic": "COBADEFFXXX"
    }'
  ```

  ```ts JS Client theme={null}
  const { seller } = await client.admin.sellers.$id.paymentDetails.mutate({
    $id: "sel_01HXYZABCDEF",
    country_code: "de",
    holder_name: "Acme GmbH",
    iban: "DE89370400440532013000",
    bic: "COBADEFFXXX",
  })
  ```
</RequestExample>

<ResponseExample>
  ```json 200 theme={null}
  {
    "seller": {
      "id": "sel_01HXYZABCDEF",
      "name": "Acme",
      "status": "open",
      "payment_details": {
        "country_code": "de",
        "holder_name": "Acme GmbH",
        "bank_name": null,
        "iban": "DE89370400440532013000",
        "bic": "COBADEFFXXX"
      },
      "updated_at": "2026-06-12T11:00:00.000Z"
    }
  }
  ```
</ResponseExample>