How we research and review

Sources first

Every factual claim — a rule, a threshold, a specification, a price range — is checked against a primary source: the governing body's policy, the standard, the regulator, or the manufacturer's own documentation. Sources are listed at the bottom of each guide.

Review dates

Each guide shows when it was last reviewed. Rules and pricing change; we re-check guides on a schedule and when a source changes.

Independence

Providers may pay us a referral fee when we introduce a buyer. That never changes what a guide says, and we do not accept payment for placement in comparisons. See the referral disclosure.

Corrections

If you spot an error, email us and we'll fix it and note the change.