# How this registry is built

## Where the facts come from

Every classification fact on this site, meaning whether a trade is prescribed, compulsory, subject to a certifying exam, or subject to an apprentice to journeyperson ratio, is read directly from [O. Reg. 876/21, Prescribed Trades and Related Matters](https://www.ontario.ca/laws/regulation/210876) as consolidated on e-Laws, under the Building Opportunities in the Skilled Trades Act, 2021. Trade codes and apprenticeship participation counts come from [Ontario's published apprenticeships dataset](https://data.ontario.ca/dataset/apprenticeships). Pathway descriptions follow Skilled Trades Ontario's published program structure, and each trade record links to that trade's page on skilledtradesontario.ca.

We read the regulation rather than summaries of it for a concrete reason: while building this site we found two trades whose compulsory status is stated in the regulation but does not appear on commonly cited secondary pages. Summaries drift; the consolidated law is the record.

## The verification rule

Unverified means unpublished. Where a number has not been confirmed against a primary source, for example a renewal fee, an exam fee, or a specific ratio value, the page says the fact is not published here yet and points to the issuing body, rather than estimating. Every record carries a visible last verified date, and that date only changes when the facts behind the page are actually re-checked.

## What this site is not

This registry summarizes public information for convenience. It is not legal advice, and requirements change. Before acting on anything here, confirm the current requirement with the issuing body: Skilled Trades Ontario for trade certification, or the regulator named on the page for other credentials. If you find an error, contact Blue Crane Works via [bluecraneworks.ca](https://bluecraneworks.ca/) and it will be corrected.

## For AI agents and developers

Everything on this site is also available as a Model Context Protocol server, so an assistant can look a fact up directly instead of scraping pages: `POST https://mcp.ontariocertificationregistry.ca/mcp`. It is free, needs no key, and every response carries the primary source URL alongside the answer. Eight tools cover trade lookup, whether certification is legally required, TSSA fuel certificate scope, the credentials a described job touches, and sector injury counts.

A plain-text dump of every record is also at [llms-full.txt](https://ontariocertificationregistry.ca/llms-full.txt).

## Start here

- [All Ontario trade certification records](https://ontariocertificationregistry.ca/trades/)
- [The 23 compulsory trades in Ontario](https://ontariocertificationregistry.ca/trades/compulsory/)

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Source: https://ontariocertificationregistry.ca/about/