Instant Classification API

Send a company description or a website URL and get back real-time industrial classifications across multiple taxonomies, plus a list of similar companies.

What you get back

A single POST request returns:

Field	What it is
RTICs	Real-Time Industrial Classifications — The Data City’s proprietary codes that classify companies by what they actually do, updated continuously.
RSICs	Real-time SIC codes — SIC codes refined with live data rather than the static codes on Companies House.
RNAICs	Real-time NAICS codes — the North American industry classification equivalent, built the same way as RSICs.
SICs	Standard Industrial Classification codes — the statutory UK codes registered at Companies House.
Similar companies	Companies with comparable business activities, ranked by similarity score.

Most classifications carry a match score, so you can decide how much to trust each result. See the response reference for what every field contains.

Who it’s for

Use this API when you need to classify companies programmatically — for lead enrichment, portfolio tagging, market sizing, or compliance screening.

How to get started

Quickstart

Authentication

OAuth2 password flow — get a JWT, use a Bearer header.

Response reference

Every field in the response, and when it’s empty.

Errors

Every error code, what it means, and what to do about it.

Rate limits & quotas

Free-tier usage quota and per-minute rate limits.

Base URL

https://instant-classification-api.thedatacity.com/api/v1

All endpoints sit under /api/v1. The interactive playground on each endpoint page lets you paste your token and send live requests.

Last modified on July 29, 2026

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​What you get back

​Who it’s for

​How to get started