---
title: "Add company to watchlist"
method: POST
path: "/watchlist"
tags: ["Watchlist"]
---

# Add company to watchlist

`POST /watchlist`

## Request

- Base URL: `https://api.companystack.co.uk`
- URL: `https://api.companystack.co.uk/watchlist`
- Auth: one of:
  - HTTP bearer
  - API key in header `X-Api-Key`

Start watching a company. Changes to it then appear in `GET /watchlist/alerts`; set `notify_email` for email alerts and `webhook_url` for signed webhook deliveries. 400 `code: company_limit_reached` when your plan's number of watched companies is used up (the count is shared with your lists).

## Request body

- object
  - `company_number` string, required
  - `notify_email` boolean
  - `webhook_url` string

## Response `201`

Company added to watchlist

## Other responses

- `401`: API key missing, malformed or revoked
- `403`: The key's plan does not include this endpoint (`code: plan_upgrade_required`, with `upgrade_url`), the key may not call it, or the key is beyond the plan's key limit after a downgrade (`code: key_limit_exceeded`: the newest keys are paused until keys are deleted or the plan upgraded)
- `404`: Company not found
- `429`: Per-minute or per-day limit reached (`code: rate_limited`, `window: minute|day`). Wait `Retry-After` seconds; when both windows are full the day is reported. A refused request does not count against either limit. A bulk lookup (`POST /company/bulk`) counts each company number in it as one request, so one that is more than you have left is refused whole, and the body adds `requested` and `fits`.

---

[API](https://skmtc.dev/companystack/apis/companystack-api.md) · [All operations](https://skmtc.dev/companystack/apis/companystack-api/llms.txt) · [OpenAPI document](https://skmtc.dev/companystack/apis/companystack-api/revisions/8f3234237d2d?raw)