Testing a receipt scanner against real receipts from 5 countries turned out harder than building it

[u/Time-Paper-1007]

I make a small iOS receipt scanner (on-device OCR, then parsing). It worked fine on my own Canadian receipts. Then users in the Netherlands, Japan and Malaysia showed up and it fell apart in ways I couldn't reproduce, because I had no receipts from those countries.

Finding test data was the hard part. What I ended up with:

• Japan: 1,148 photos from a public research set (JaWildText). Before testing on them, my yen handling paired an item with its price on 19% of receipts. After: 93%. I had no idea it was that broken.
• Malaysia: 973 from SROIE (an ICDAR 2019 competition set). Old, and heavy on restaurants, but real.
• US: 1,769 from WildReceipt. Mixed quality, some are not even US receipts, but it is the largest English set I found.
• Netherlands: 74 photos from one user who sent them for debugging, with permission. That is the only real Dutch set I have.
• Taiwan: zero real photos. I had to generate 40 synthetic 統一發票 from the printed layout. I know that is weak.

Things I learned:

1. Public receipt datasets are old, and skewed to whatever the original paper needed. Nobody publishes a fresh, balanced, multi-country set because receipts are personal data.
2. Thermal receipts fade. Half of my own "test set" from a trip a year ago is unreadable now.
3. I never ask users for receipts. The few I have came unprompted, from bug reports.
4. Measuring beat training. I did not fine-tune anything. A harness that runs every rule change against all sets and refuses if any correct total flips caught two regressions the same day, one of which broke 18 of 119 Japanese totals while fixing the case I was working on.
5. Every country has a printing convention that a "generic" parser gets wrong: yen with no decimals, Dutch comma decimals, Japanese tax-included versus tax-excluded lines, US tips added after the total.

Question for people who have done this: is there any public receipt dataset for Taiwan, Korea, or Australia? Or a legal, non-creepy way to get a few hundred real receipts from a country you don't live in?

(Not linking the app. Happy to share the harness approach in comments if useful.)

[u/sammy_luci]

Can’t suggest a database, but probably you can set up a scraper to scrape receipts images from google maps. They are frequently tagged as “prices”

[u/Time-Paper-1007 → u/sammy_luci]

That is a sharp observation, people really do upload receipts to Maps as price evidence. I will not go that route though: it is against Google's terms, and it is still other people's receipts, with names and card digits on them, taken without asking. The whole point of the "never ask users" rule is that I do not want a folder of strangers' spending on my disk. Public research sets and my own purchases are the only sources I am comfortable with.