CorpNet Employer Tax Registration API

The CorpNet Employer Tax Registration API lets partners register employers for state and federal tax accounts (unemployment insurance, withholding, and equivalents) across all 50 U.S. states, including California. A single endpoint handles every state.

Where to start

If you want to…Go here
Understand the API at a high levelOverview
See the request body schema and required fieldsCreate a tax registration order
See the GET response shape (status summary)Retrieve tax registration order details
Set up authenticationAuthorization and API Key
Find common errors and gotchasFAQ

Endpoints

MethodPath
POST/api/api-partners-v10/tax-reg-50states/
GET/api/api-partners-v10/tax-reg-50states/{orderGuid}

Hosts: api.corpnet.com (production), api.staging24.corpnet.com (staging). Both APIs (Tax Registration and Business Formation) share hosts.

Authentication

Bearer token, issued by CorpNet during partner onboarding. The same token authenticates both APIs; entitlement follows your partner agreement.

Authorization: Bearer <your_api_key>

See Authorization for the full auth model.

Notes on the response contract

  • POST 201 echoes the full submitted order back at data.partnerOrder.*, plus assigned id and orderGuid.
  • GET 200 returns a summary only — id, orderGuid, orderPhase, orderStatus, accountNumbers, taxRates, agencyAccounts. Submitted business details, state info, and responsible parties are not included in the GET response. Retain a local copy of the submission if you need to re-display it.
  • Not-found semantics: GET on a non-existent orderGuid currently returns HTTP 400 (rather than 404) with body {"statusCode": 200, "message": "success", "data": {"partnerOrder": null}}. Detect not-found by checking data.partnerOrder === null, not by trusting the status fields.

For the full request and response schemas — including conditional field rules, per-entity-type enum tables, and validation gaps to be aware of — see the autogen Create and Retrieve reference pages and the Overview.