Local
Taiwan ID numbers, invoice codes, year systems — quick checks for daily life.
All Local
ROC / Gregorian Year Converter
Convert between Taiwan ROC (民國) and Gregorian years instantly in either direction — for tax forms, government applications, health insurance paperwork, and historical documents. Runs locally.
Uniform Invoice Validator
Validate any 8-digit Taiwan business number (統一編號 / 統編) checksum locally using the post-2023 Ministry of Finance rule (total divisible by 5), with a per-digit calculation ladder; the 7-in-7th-digit special case is supported too. Useful for accounting, e-invoice filtering, and B2B onboarding. Nothing is uploaded.
Year System Converter
Cross-reference Gregorian, ROC, Japanese era (Meiji through Reiwa), and Buddhist years — convert a Reiwa, Heisei, or Showa year to Western years instantly. Runs locally; nothing is sent out.