Every rule in the database is linked to a source. A rule is marked as verified only when an official source confirms it: a foreign ministry, border authority, embassy or the official legal text.
Blogs, media and guides are used only to find out what needs checking. Such rules are marked as based on a secondary source.
So that any nationality and any country can be checked, the basic “passport → country” answer for all 199 countries comes from the open Passport Index dataset. It is labelled as a secondary source with its data date. Where we have a rule built from an official source, that rule is shown instead.
Every rule has a check date. Rules older than 90 days and rules with an end date are re-checked first.
Rule changes are published in the “Rule changes” section only with a link to a source.
This site does not give legal advice. Check the official source before you travel: border officers make the final decision on entry.