---
title: "Find companies by sector, place, age and size — or lookalikes"
method: GET
path: "/prospects"
tags: ["Prospects"]
---

# Find companies by sector, place, age and size — or lookalikes

`GET /prospects`

## Request

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

Filters combine with AND; comma-separated values with OR. Needs at least one narrowing filter. `like={company_number}` searches that company's 4-digit SIC class (its postcode area first), scores up to 500 candidates on sector, location, size and age, and returns the closest with a `similarity` of 0–100. New-incorporation lists: `incorporated_from=…&sort=newest`.

## Query parameters

- `sic` string
- `postcode` string
- `town` string
- `status` string
- `category` string
- `accounts_category` string
- `incorporated_from` string, date
- `incorporated_to` string, date
- `min_age_years` integer
- `max_age_years` integer
- `min_turnover` integer
- `max_turnover` integer
- `min_employees` integer
- `max_employees` integer
- `min_net_assets` integer
- `max_net_assets` integer
- `has_charges` boolean
- `exclude_overdue` boolean
- `like` string
- `sort` 'newest' | 'oldest' | 'name'
- `limit` integer
- `cursor` string

## Response `200`

Matching companies

## Other responses

- `400`: Validation error
- `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`: Lookalike seed 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)