Taiwan Business Number Validator

What a unified business number is

The unified business number (統一編號, or 統編) is the 8-digit identifier every company, branch, sole proprietorship and registered organisation in Taiwan receives from the Ministry of Economic Affairs or the tax office. You need it to have an invoice (發票) issued to your employer, to register a vendor in accounting software and to file withholding statements. The last digit is a check digit, and this tool reproduces the official check so typos are caught before they reach a form.

How the checksum works

• Each of the eight digits is multiplied by its weight: 1, 2, 1, 2, 1, 2, 4, 1.
• The digits of every product are added together (7 × 2 = 14 becomes 1 + 4 = 5), then the eight results are summed.
• Since April 2023 the total must be divisible by 5; before that it had to be divisible by 10. The change doubled the supply of numbers because the old ones were running out.
• When the seventh digit is 7, its product 28 gives a digit sum of 10, which may count as 1 or 0, so total + 1 divisible by 5 also passes.
• A passing checksum only means the number is well formed, not that the company exists or is still registered.

Looking a company up

To see who a number belongs to, search it on the Ministry of Economic Affairs registration portal (商工登記公示資料查詢服務, findbiz.nat.gov.tw) or the Ministry of Finance tax registration lookup (稅籍登記資料公示查詢); both are free and show the registered name, address and status.

Privacy

Numbers are checked on your device. Nothing is sent to a server or recorded.