Requirements

From composer.json:

PHP ^8.4
ext-dom — the live EU TEDB source parses the Commission's SOAP responses with DOMDocument/DOMXPath.
ext-zlib — the US boundary indexes are published gzipped (5.4 MB across the 24 SST states instead of 20 MB) and inflated on read.
Laravel ^13 (illuminate/contracts, illuminate/support, illuminate/http)
cboxdk/laravel-geo ^0.5 — the canonical jurisdiction reference every assessment binds to.
brick/money ^0.14 — exact integer-minor-unit money for amounts and rate maths.

No migration is required. Rate data is supplied by a TaxRateSource; the default binding ships representative national rates for out-of-the-box use.

Why Laravel 13 only

A library should install on the current and previous Laravel major, and this one does not. That is a deliberate decision with a specific external cause, not an oversight:

brick/money ^0.14 — the exact-money library every amount and rate calculation runs through — requires brick/math ~0.15 or newer.
laravel/framework 12.64 caps brick/math at ^0.11|^0.12|^0.13|^0.14.

The ranges are disjoint, so the two cannot be installed together. Supporting Laravel 12 would mean pinning brick/money back to ^0.11 — three minors and a different rounding surface — for a tax engine, where the money library's behaviour is the calculation. Reach is not worth that trade.

Note that illuminate/support, illuminate/contracts and illuminate/http never require brick/math themselves; the cap lives in the full framework package, and only from 12.64 onward. The constraint will be widened to ^12.0 || ^13.0 if a Laravel 12 patch relaxes it — nothing in this package's own graph prevents it.