How is the Belarusian UNP check digit calculated?

Each of the first eight characters is mapped to a numeric value, multiplied by the weights 29,23,19,17,13,7,5,3, and summed. The remainder modulo 11 is the expected check digit, which must equal the ninth character.

How many characters is a UNP?

Nine characters. Newer UNPs are all digits, while some older codes contain a Latin letter in an early position, which this tool maps to its numeric value before checking.

What if the checksum equals 10?

A control digit of 10 cannot be represented in a single position, so a UNP whose checksum resolves to 10 is treated as invalid by the official rule and rejected here.

Does a valid UNP mean the taxpayer is registered?

No. A valid check digit only confirms the UNP is internally consistent. To confirm the taxpayer is currently registered, check with the MNS of Belarus.

Is my UNP sent anywhere?

No. The check runs entirely in your browser, so the code never leaves your device and nothing is logged or transmitted.

Belarus UNP Validator

The UNP (payer’s account number) is the 9-character taxpayer identifier issued by the Ministry of Taxes and Duties (MNS) of Belarus. It is required on invoices, e-invoicing submissions and customs declarations. The final character is a modulo-11 check digit, so a single mistyped character is detectable. This free validator runs the exact algorithm in your browser.

How it works

The official check-digit algorithm operates on the first eight characters:

Map each character to a numeric value: digits map to themselves, and the Latin letters used in older codes map via a fixed table (A=10, B=11, C=12, E=13, H=14, K=15, M=16, O=17, P=18, T=19).
Multiply each value by its weight: 29, 23, 19, 17, 13, 7, 5, 3.
Sum the products and take the remainder control = sum mod 11.
If control equals 10 the UNP is invalid. Otherwise the ninth character must equal control.

Example

For a UNP whose first eight characters are all digits, the tool multiplies each by its weight, sums, and compares sum mod 11 against the ninth digit. If they match, the UNP is valid; change any character and the expected check digit no longer matches.

A valid check digit confirms the UNP is well-formed, not that the taxpayer is registered. All processing stays on your device.