Your Japan Trip Receipts, in Your Own Currency
Eleven receipts from a trip to Japan in March: a FamilyMart, a Daiso, a drugstore in Kyoto, a supermarket with a discount sticker on half the items, a Yoshinoya breakfast for three. Scanned on a Canadian phone, they came back as barcodes for item names and two totals that were simply wrong. Version 2.3.0 is what we built after finding out why.
The phone that couldn't see Japanese
The receipts themselves were fine. The text recognition that reads them is Apple's, and it is excellent at Japanese. The catch is how it chooses a script: it takes the first language it is given and uses that model for the whole image. A phone set to English gave it "English, then Chinese", and every kana and kanji on the page simply vanished. What was left was numbers, so the parser saw a list of prices with no names and did the only thing it could: it invented.
We had never seen this because our Japanese test set had always been run with Japanese first. The gap only showed when a real English-language phone scanned a real Japanese receipt.
The fix sounds trivial and is not: you cannot just add Japanese to the list. We measured that on 44 Japanese, 74 Dutch, 40 Malaysian and 40 Taiwanese receipts, and appending Japanese changed nothing. Automatic language detection never picked Japanese either. What works is a second pass, Japanese first, and a vote: the share of Japanese and Chinese characters in that second pass. On every Japanese receipt it was at least 21%. On every Dutch or Malaysian receipt it was at most 7%. Taiwanese receipts score high with no kana at all, which routes them to a Chinese-first pass. Both passes run at the same time, so an English receipt is not slower.
Yen is not dollars
Once the app could read the receipts, it saved ¥2,530 as 2,530 and showed it as $2,530.00. There was no notion of currency per receipt at all. That is fixed in 2.3.0, and the design took some thought:
- The currency comes from the paper. ¥ with kana means yen; NT$ or a 統一發票 header means New Taiwan dollars; € and £ are what they look like. A bare "$" stays your own currency. The AI is never asked to guess.
- The receipt is stored converted, at that day's exchange rate, so your budgets, charts and exports keep summing one currency. A ¥2,530 lunch adds about $22 to your month, not 2,530.
- The printed amount is never lost. Every foreign receipt keeps its original total, the rate used and the date of that rate. The detail screen shows both, and a "Show in JPY" button flips the whole receipt, item by item, to what the paper says.
- You choose what lists show. Settings → Currency has a switch: converted amounts with the printed one underneath, or the printed amount with the converted one underneath.
- Offline scans still work. No connection means the receipt is saved unconverted, in its own currency, and converts itself the next time the app is online.
The eleven receipts, after
| Receipt | Printed total | Result |
|---|---|---|
| FamilyMart, two teas | ¥276 | right, both teas as separate items |
| INGNI, one sweater plus 10% tax | ¥2,530 | right, $22.41 at 0.008856 |
| Drugstore, three items, one with a quantity line | ¥448 | right, after a rule for the Japanese quantity-line layout |
| WEGO, tax-included clothing receipt | ¥1,320 | right, after the parser learned not to subtract an included tax |
| Yoshinoya, five dishes | ¥3,429 | right, every dish |
| Life supermarket, ten items, eight discount stickers | ¥2,644 | total right, one item price still off |
| Airport drugstore | ¥2,140 | right, after fixing a crop that shaved the last digit off every price |
The supermarket receipt is the honest limit. Ten items each followed by a discount line is the densest layout we have met, and the step that pairs prices with their items still gets scrambled on it. The total and the date hold; one line item can be wrong. That one is next.
What this means if you travel
Scan the receipts on the trip, or on the plane home, in whatever language your app is set to. They land in your own categories, in your own currency, with the yen kept alongside. And if you live in Japan and budget in English, the workaround we used to recommend, switching the app language to Japanese, is no longer needed.
Version 2.3.0 is on the App Store now. If a receipt from your travels comes out wrong, the Report button on the receipt sends us the photo, with your consent, and it becomes a test case for the next release.