How we verify
Every number on this site came from a document published by whoever sets the rule. This page explains what that means in practice, because "we check our sources" is a claim anyone can make.
What counts as a source here
| Subject | Authoritative source | Not used as a source |
|---|---|---|
| Consumption tax, tax-free shopping | National Tax Agency Q&A and notices; Ministry of Finance reform outlines | Retailer explainers, travel media |
| Lodging tax | The municipality's own ordinance or tax page; Ministry of Internal Affairs consent notices | Aggregator tables of "cities with a lodging tax" |
| Rail fares and passes | The operator's tariff pages and press releases | Reseller sites, which show their own prices |
| Customs, immigration | Japan Customs, Immigration Services Agency, Ministry of Foreign Affairs | Forum posts, community wikis |
| Holidays and astronomical dates | Cabinet Office published data; National Astronomical Observatory almanac | Calculated approximations |
Where a source exists only in Japanese — which is most of the time — we read the Japanese and link to it anyway. An English page that summarizes it is linked as a convenience, never as the basis for a number.
Rates live in data files, not in sentences
A rate written into an article has to be found again by someone who remembers it is there. Every rate on this site is stored once, in a data file that also holds:
- the date the rule takes effect, and the date it stops applying
- the source it came from
- the date a human last read that source
Pages render from that file. So a rate change is one edit in one place, and the calculators pick the rule that applies to the date you entered rather than describing "the current system". A stay in Kyoto on 28 February 2026 and a stay on 1 March 2026 are taxed differently, and the same page answers both correctly without being rewritten.
"Last checked" is a date, not a promise
Each tool page shows when its figures were last compared with the source. That is a claim we can actually keep: a human opened the authority's page on that day and compared it line by line. It is not a promise that nothing has changed since, and a page that has not been checked recently says so by showing an old date rather than by hiding it.
What we do when something cannot be confirmed
- We leave it out. The lodging tax calculator covers the municipalities whose own ordinance or tax page we have read — it states its own count on the page, and in 2026 there are more places levying the tax than it covers. Filling the rest from a secondary table would make the tool look complete and quietly make it wrong.
- We say which part is unconfirmed, rather than dropping the whole topic.
- An unreachable page is not a repealed rule. Several Japanese government sites refuse automated requests, and government pages are reorganized without redirects. A source that returns an error gets opened by hand before anything is changed.
Corrections
If a figure here is wrong, tell us. With a link to the authority's page we can usually verify and fix it the same day. Corrections that change a number are noted on the page that carried it.