SOSFiler Partner API Customer Site
Company formation infrastructure

Launch business formation inside your product.

Create quotes, submit formations, send customers to hosted checkout, track state filing progress, and retrieve finished documents through one API.

$297Partner setup review and API onboarding.
$29+SOSFiler service fee per formation, plus official fees.
API + hostedUse pure API calls or hosted checkout while your integration matures.

Apply for API access

After payment and approval, SOSFiler issues your API key once. Store it in your backend.

How access works

  1. Submit your partner application.
  2. Pay the setup fee or complete manual billing review.
  3. SOSFiler approves the partner account.
  4. Your one-time API key is issued and shown once.
  5. Your backend calls the Partner API with a bearer token.

First API call

curl https://sosfiler.com/api/v1/partners/formations \
  -H "Authorization: Bearer sos_live_..." \
  -H "Content-Type: application/json" \
  -d '{
    "external_order_id": "partner-order-123",
    "formation": { "...": "..." },
    "success_url": "https://yourapp.com/success",
    "cancel_url": "https://yourapp.com/cancel"
  }'