OneInvoice Support
We reply within 2 business days. The fastest way is Settings → Help and feedback → Send feedback in the app; it includes your diagnostic ID so we can look into the problem.
Email: candy66861@gmail.com (please include your diagnostic ID from Settings → Help and feedback).
Frequently asked questions
Do I need an account?
No. There is no sign-up at all. Open the app and create your first document.
What is free, and what does the purchase unlock?
You can issue 3 documents for free (export, share or print). Drafts, editing, payment records, backups and CSV export are never limited. A one-time purchase unlocks unlimited documents, removes the small "Created with OneInvoice" line and includes all future updates. There is no subscription.
How do I restore my purchase on a new iPhone or iPad?
Sign in with the same Apple ID and open Settings → Purchase → Restore purchase. Family Sharing is supported if it is enabled for the purchase.
How do I move my documents to a new phone?
With iCloud turned on, install the app on the new phone with the same Apple ID and your documents appear automatically. Without iCloud, use Settings → Backup and sync → Export backup on the old phone, send the .oneinvoice file with AirDrop or Files, then choose Import Backup on the new phone.
My documents are not syncing.
Check that iCloud Drive is on and that OneInvoice is allowed in iOS Settings → [your name] → iCloud. Sync can take a few minutes on a slow connection. Settings → Backup and sync shows the current status.
Can I send documents with KakaoTalk, LINE or WhatsApp?
Yes. Tap Send, then the messenger button (or Share) and choose the app in the share sheet. You can send a PDF or an image (JPG).
Does the app support the Japanese invoice system (インボイス制度)?
Yes: registration number (T + 13 digits), totals and consumption tax per rate, reduced-rate marks, rounding options, tax-exempt mode, withholding tax, seals, bank details and Japanese era dates.
Is a document from OneInvoice a tax invoice or e-invoice?
OneInvoice creates business documents as PDF files based on the rates and settings you enter. It does not issue government e-invoices (such as Korean 세금계산서, XRechnung/ZUGFeRD, VERI*FACTU or CFDI) and does not provide tax advice. Please check the requirements that apply to your business.
How do I get a refund?
Purchases are handled by Apple. Request a refund at reportaproblem.apple.com.
How do I delete my data?
Delete documents in the app, and remove the iCloud copy in iOS Settings → [your name] → iCloud → Manage Storage. See the Privacy Policy for the anonymous statistics we keep and how to request deletion.