Beta status and responsibility

The register's data is in beta. It is read from primary sources — statutes, tax-authority publications, official rate tables — and every rate carries the source and the date it was captured. That is a much better starting point than a scraped list, and it is still not a guarantee. There will be errors nobody has found yet.

The engine is the same: it models a large amount of law, it is tested against an independent reference corpus, and it is young. Both halves get corrected as errors surface.

What this package does guarantee

Narrow things, and it holds them firmly:

It does not invent numbers. Every rate comes from a published record with its provenance attached. Where nothing published answers, the engine raises an exception rather than returning a plausible figure.
It says when it is unsure. confidence and limitedBy mark an answer that is the best available rather than exact, and each limit carries the one step that would close it.
It is reproducible. Pin a release and the same query gives the same answer, offline, for as long as you keep that release installed.

What it does not

It cannot know what it does not know. Confidence::Authoritative means "the published data answered exactly what was asked" — not "this figure is correct in law". A rate transcribed wrongly, a rule that changed without the authority publishing it clearly, a category read more narrowly than a tax office would read it: none of these leave a mark on the assessment.
It is not tax advice. Which regime a business falls under, whether a supply is what you think it is, whether a registration is required, what gets filed and when — those are questions for a qualified adviser in that jurisdiction.
It does not file anything. The engine calculates and explains. Registration, returns, remittance and e-invoicing mandates stay outside it.
It carries no warranty. The package is MIT and the register's data is licensed separately; both are provided as-is, without warranty of any kind. Neither licence makes anyone liable for a tax outcome.

What stays yours

You remain responsible for the tax you charge, collect and file. Practically, that means three habits worth building in from the start:

Act on the flags. OrderAssessment::needsReview() exists so that an uncertain answer can be caught before an invoice goes out rather than at an audit. Decide what your application does with it — block, queue for review, or record it — and make that decision deliberately.
Sanity-check the places that matter to you. The countries and categories you sell most in deserve a one-off check against your own adviser's numbers, and a re-check when you enter a new market. A hundred jurisdictions you never sell into being right is worth less than the three you live in.
Store what you charged, and why. Keep the treatment, the reason, the release version and the provenance on the order — see the checkout recipe. When a rate turns out to have been wrong, that record is the difference between correcting the affected invoices and guessing at them.

Reporting an error

A wrong number is worth more to us than a working one, because it is the only way the data improves. Open an issue on cboxdk/laravel-tax with the query, the answer you got and the answer you expected, plus the release version from $assessment->rate?->provenance?->version. That last field is what makes a report reproducible instead of anecdotal.

Errors in the data are corrected in the register and reach you through tax:data:sync; errors in the logic are fixed in the package. The reply will say which one it was.