Taiwan / Identity numbers
Taiwan ID and Business Number Validator (身分證字號、統一編號)
Check Taiwan national ID and resident certificate numbers, with the place and sex they record, and 8-digit Unified Business Numbers (統一編號), under the check rule in force since 2023.
Taiwan ID and Business Number Validator (身分證字號、統一編號): An ID is a letter for the place of first registration, a digit for sex (1 male, 2 female; 8 and 9 on resident certificates issued since 2021), seven digits, and a check digit computed from the letter's two-digit code and the other digits. A business number's digits are weighted 1, 2, 1, 2, 1, 2, 4, 1, the digits of each product added, and the total must divide by 5, a rule the Ministry of Finance introduced in 2023 in place of 10, so older numbers pass both. Every business number python-stdnum accepts under the older rule is accepted here. Runs 100% locally in your browser with zero server file uploads.
- Category
- Business & admin tools
- Runs
- In your browser
- Cost
- Free · no sign-up
- Availability
- Ready to use
Runs entirely in your browser
An ID's letter is the place of first registration, the next digit the sex (1 male, 2 female; 8 and 9 on resident certificates since 2021), and the last digit a check digit. A business number's digits, weighted 1, 2, 1, 2, 1, 2, 4, 1, must add up to a multiple of 5; it was 10 until 2023, so older numbers pass both. Only the format is checked; nothing leaves your browser.
A worked example
For A123456789, the letter A is 10, so the sum is 1 × 1 + 0 × 9 + 1 × 8 + 2 × 7 + 3 × 6 + 4 × 5 + 5 × 4 + 6 × 3 + 7 × 2 + 8 × 1 = 121. The check digit makes the total a multiple of 10, so it is 9.
For dates on Taiwanese documents, use the Minguo year converter; for mainland numbers, the Chinese ID validator.
A business number, worked through
For 04595257, the digits times 1, 2, 1, 2, 1, 2, 4, 1 give 0, 8, 5, 18, 5, 4, 20, and 7. Adding the digits of each product, 0 + 8 + 5 + 9 + 5 + 4 + 2 + 7 = 40, which divides by 10 and so passes both the old rule and the current one, a total divisible by 5.
How to use it
- Type or paste ID numbers or 8-digit business numbers, one per line.
- Read which are valid, and the details each ID holds.
- For an ID that fails, see the check digit it should have.
Privacy & limitations
Numbers are checked in your browser and never sent anywhere. An ID number is personal data: check only numbers you are allowed to handle.
Related tools
Frequently asked questions
Why did the business number rule change?
The supply of numbers that satisfy the old rule was running out, so from 2023 a total divisible by 5 is enough; numbers issued before still divide by 10.
What does the letter at the start mean?
The city or county where the person was first registered, such as A for Taipei City; the letters follow the old administrative divisions.
Does a valid result mean the number exists?
No: only that it is correctly formed.
Free tool · runs in your browser · no account required