---
title: "[Sandbox] Add blocked reason"
method: POST
path: "/filings/{filing_id}/simulate/add_blocked_reason"
---

# \[Sandbox\] Add blocked reason

`POST /filings/{filing_id}/simulate/add_blocked_reason`

## Request

- Base URL: `https://sandbox.checkhq.com`
- URL: `https://sandbox.checkhq.com/filings/{filing_id}/simulate/add_blocked_reason`
- Auth: API key in header `Authorization`
- TypeScript: <https://skmtc.dev/checkhq/apis/check-api/docs/filings/:filing_id/simulate/add_blocked_reason/post.ts> (a function with typed inputs; its response is checked against the schema)

Add a blocked reason to a filing to simulate a filing failure, transitioning the filing to `blocked`. Sandbox-only: in production this endpoint returns a 404.

The filing must be in `pending` or `blocked` status. Most blocker IDs from the [Filing blockers](https://docs.checkhq.com/docs/tax-filings#filing-blockers) table are accepted. Blockers that Check sets automatically (`applied_for_tax_id`, `missing_tax_funds`, `collection_failed`, `company_bad_standing`) return `rule_violation`. Blockers that apply only in certain cases, such as `incorrect_experience_factor` (Washington L&I filings only), return `manual_issue_policy_violation` when added to a filing they don't apply to, with a message explaining why. Returns the updated filing. An `updated` webhook with the `company_filing` topic is sent.

## Path parameters

- `filing_id` string, required

## Request body

- object
  - `blocked_reason` string, required: ID of the blocker to add to the filing. See the [Filing blockers](https://docs.checkhq.com/docs/tax-filings#filing-blockers) table for the full list.
  - `note` string, nullable: Optional note to attach to the blocked reason. If the blocked reason is already present on the filing, the note is updated.

## Response `200`

200

- object
  - `id` string
  - `company` string
  - `year` integer
  - `period` string
  - `label` string
  - `jurisdiction` string, nullable: Lowercase region code for the filing (`fed` or lowercased ISO 3166-2:US region code).
  - `agency` string, nullable: ID of the Agency that receives this filing.
  - `due_at` string
  - `filed_at` string, nullable
  - `closed_at` string, nullable
  - `document` string, nullable
  - `filing_attempts` integer
  - `amends` string[]
  - `amended_by` string[]
  - `status` string
  - `status_history` object[]
    - `status` string
    - `status_at` string
    - `blocked_reasons` object[]
      - `type` string
      - `resource_type` string, nullable
      - `resource` string, nullable
      - `note` string, nullable

## Other responses

- `400`: 400
- `404`: 404

## Changes

- **2026-11-03** `5a54f5eb888b`: 1 info
  - endpoint added

[Operation history](https://skmtc.dev/checkhq/apis/check-api/changes/filings/:filing_id/simulate/add_blocked_reason/post.md)

---

[API](https://skmtc.dev/checkhq/apis/check-api.md) - [All operations](https://skmtc.dev/checkhq/apis/check-api/llms.txt) - [OpenAPI document](https://skmtc.dev/checkhq/apis/check-api/revisions/5a54f5eb888b?raw)