Privacy policy
The short version: what you tell Yoo Dai about yourself stays on your phone and in your own iCloud. We never see your passport, your answers or your visa.
Last updated 27 October 2026.
No account
You do not sign up. The app never asks for your name, email address or a password.
What stays on your phone
Your answers to the visa questions, your passport details, your stay and trip dates, your border crossings, your checklist, your plans, your saved places and events, and the photos of documents you add. They are kept on your iPhone and, if you use iCloud, synced through your own iCloud account so they reach your other devices. Apple holds that copy for you; we cannot read it.
When you scan your passport, the camera reads the two lines at the bottom of the photo page on the phone itself. The picture is not kept and not sent. The app keeps your nationality, date of birth, sex and expiry date, never the passport number or your name.
If you have an Apple Watch, your phone sends a short summary to it directly: days left on your stay, days in Thailand this year, your next plans and your office day list.
What reaches us, and why
Yoo Dai's server is run with Supabase in Singapore. It holds only the following.
Tips and reports you choose to send. When you send a tip or tell us how a visit to an office went, we receive what you wrote, where in the app you sent it from, the app version and a random number made on your phone. That number is not linked to you; it lets your phone delete what it sent and lets us thank you in the app when we use your tip. Your nationality is sent with an office report only if you turn that on. You can delete everything you sent at any time in More, Settings.
Notifications. If you allow notifications, we keep the address Apple gives your phone for them, which kinds of alerts you turned on (emergencies, immigration, travel, news, events, destinations), the towns you chose for alerts, and the app version. When a rule changes we send every phone the same silent signal; your phone checks for itself whether the change touches your visa, so we never learn which visa you are on.
Office day on the Lock Screen. If you set an office day, the office, its opening hours, the day you go, how many things are left to bring and up to two tips are kept so the card can appear on your Lock Screen that morning. Nothing about your visa or passport is sent.
The rulebook, news, places and events. Your phone downloads these like any web page. We do not keep a record of who downloaded what.
Location
Only if you turn it on. Yoo Dai asks for your location while you use the app, for two things. To show our picks when you arrive at a place, your iPhone tells the app when you get there; that stays on the phone. To choose your towns for alerts, Apple turns your position into a town name, and only that town name is sent to Yoo Dai. Your exact location is never sent to us.
When you contact us
The contact form on this website sends your name, email address, topic and message to the server of davidpaterni.com, which emails it to us. The partner form sends the business name, a contact name, email and phone number to Yoo Dai's server. We use these only to reply to you.
Membership and payments
Membership is sold and billed by Apple. We do not see your card or your Apple Account details.
No tracking and no advertising
Yoo Dai has no advertising, no analytics tools and no tracking across other apps or websites. We do not sell or share data.
Partners
Some links and codes in the app lead to businesses that may pay Yoo Dai a fee. They are marked Partner or Sponsored. When you open one, that business sees that you came from Yoo Dai and handles your data under its own policy.
Deleting your data
Delete the app to remove what is on the phone. Manage your iCloud storage in the iPhone Settings to remove the synced copy. In Yoo Dai, More, Settings, Delete everything I sent removes your tips and reports from our server. Turning notifications off in the iPhone Settings stops us reaching the phone.
Children
Yoo Dai is made for adults dealing with their own visa.
Contact
Questions about privacy: use the contact page. We will say here when this policy changes.