Tool suggestion: Unified Social Credit Code checker — offline structure and check-digit validation for Chinese company codes

Suggesting a small browser tool I maintain. I have listed what it does not do below so the editors can judge it independently.

Why it might fit: the company-registry entries on the China-related resources page mostly need a Chinese mobile number, a China IP, or a login before they return much. This one needs none of those, because it does not query anything — it works on a code you already have.

## URL

https://currawongweb.com/verify/china-usci-checker/

## Description

Paste an 18-character Unified Social Credit Code from a Chinese business licence. The page splits it into the five parts defined by GB 32100-2015 (registration authority, entity category, administrative division, subject identifier, check character) and recalculates the check digit.

It also reads the first two characters, which separate an enterprise (91) from an individually-owned business (92) or a farmers' specialised cooperative (93) — a distinction a licence photo does not make obvious.

Everything runs in the browser. The code is not transmitted, stored or logged.

## Cost

* [x] Free
* [ ] Partially Free
* [ ] Paid

## Level of difficulty

Beginner. Paste the code, read the breakdown.

## Requirements

A modern browser. No account, no Chinese phone number, no China IP address, no API key.

## Limitations

- A passing code only means it was transcribed correctly. It does not show that the company exists, is still trading, or is permitted to export.
- It cannot tell that a well-formed code belongs to a different company than the one named on the document.
- Structure only. There is no registry lookup behind it, so it says nothing about status, penalties or business scope.

## Ethical Considerations

It is a transcription check, not a verdict on a company. The page says so above the input box, because a green tick is easy to over-read.

## Guides and articles

A short study on how much protection the check digit actually gives, with the data deposited on Zenodo under CC BY:

https://currawongweb.com/verify/check-digit-protection-study/
https://doi.org/10.5281/zenodo.21867383

## Tool provider

Currawong Web. I maintain the page. Happy for it to be one row on the China-related resources page rather than its own entry, if that fits better.

Locate the China-related resources page in the toolkit and review how comparable entries are structured. Add the provided Unified Social Credit Code checker URL with a concise description and its stated limitations, then verify the entry renders consistently with the existing resources.

Written by the indexing model from the issue text.