> ## 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 Professional Details

> Create or update a seller's legal and tax details.

Creates the seller's professional 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="corporate_name" type="string">Registered corporate name.</ParamField>
<ParamField body="registration_number" type="string">Company registration number.</ParamField>
<ParamField body="tax_id" type="string">Tax identification 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="professional_details" type="object">
      <Expandable title="properties">
        <ResponseField name="corporate_name" type="string">Registered corporate name.</ResponseField>
        <ResponseField name="registration_number" type="string">Company registration number.</ResponseField>
        <ResponseField name="tax_id" type="string">Tax identification number.</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/professional-details' \
    -H 'Authorization: Bearer <token>' \
    -H 'Content-Type: application/json' \
    -d '{
      "corporate_name": "Acme GmbH",
      "registration_number": "HRB 123456",
      "tax_id": "DE123456789"
    }'
  ```

  ```ts JS Client theme={null}
  const { seller } = await client.admin.sellers.$id.professionalDetails.mutate({
    $id: "sel_01HXYZABCDEF",
    corporate_name: "Acme GmbH",
    registration_number: "HRB 123456",
    tax_id: "DE123456789",
  })
  ```
</RequestExample>

<ResponseExample>
  ```json 200 theme={null}
  {
    "seller": {
      "id": "sel_01HXYZABCDEF",
      "name": "Acme",
      "status": "open",
      "professional_details": {
        "corporate_name": "Acme GmbH",
        "registration_number": "HRB 123456",
        "tax_id": "DE123456789"
      },
      "updated_at": "2026-06-12T11:30:00.000Z"
    }
  }
  ```
</ResponseExample>