INN generator online free — generate test INN with checksum. Random individual INN (12 digits) and legal entity INN (10 digits), region selection.
Test INN generator for developers. Generates valid numbers with correct check digits. Legal entity INN — 10 digits, individual INN — 12 digits.
Test INN Generator — for Development and Testing
The generator creates syntactically valid INN numbers with correct check digits for use in test environments, software development, and automated testing. Generated numbers do not belong to real individuals or organizations.
INN Number Structure
| Type | Length | Structure |
|---|---|---|
| Legal entity INN | 10 digits | NNNN (tax office code) + XXXXX (serial) + C (check digit) |
| Individual / IP INN | 12 digits | NNNN (tax office code) + XXXXXX (serial) + CC (two check digits) |
The first 2 digits represent the Russian region code (77 — Moscow, 78 — Saint Petersburg). The next 2 are the local tax office number. Our generator lets you choose from 20 major Russian regions.
Check Digit Algorithm
The check digit is computed as a weighted sum of preceding digits modulo 11, then modulo 10. Weights for 10-digit INN: 2, 4, 10, 3, 5, 9, 4, 6, 8. This guarantees detection of accidental typos when entering the number.
Test INN Applications
- Software development — populating forms when building accounting and ERP systems
- Automated testing — generating valid data for Selenium, Cypress, Playwright
- Demos — screenshots and videos without exposing real client data
- Education — materials for accounting and taxation courses
Frequently Asked Questions
Can generated INNs be used in official documents?
No. Generated numbers are intended solely for testing. To obtain a real INN, you must apply to the Federal Tax Service.
Are generated numbers unique?
Numbers are generated randomly and pass checksum validation. They could theoretically match a real INN, but the probability is extremely low.
Why choose a region?
The first 4 digits of an INN are the tax office code (region + office number). Selecting a region generates numbers matching a specific Russian region, useful for testing regional logic.
How to validate an INN?
Use our INN validator — it checks the digits and decodes the number structure.
To generate SNILS numbers use the SNILS generator, and to check OGRN — the OGRN validator.
Useful articles
OGRN: How to Validate and Decode a Company Registration Number
A breakdown of the OGRN structure, the meaning of each digit group, the check digit verification algorithm, and the differences between OGRN and OGRNIP for sole proprietors.
SNILS: Format, Check Digit, and Test Data
A breakdown of the SNILS format, the check digit algorithm, its role in the social security system, and why developers need test data.