CNPJ Generator

Generate Brazilian CNPJ numbers for testing

XX.XXX.XXX/XXXX-XX

Click 'Generate' to create your first XX.XXX.XXX/XXXX-XX

About CNPJ Generator

CNPJ (Cadastro Nacional da Pessoa Jurídica) generator creates valid formatted Brazilian corporate tax identification numbers for testing and development purposes. Supports both the traditional numeric format and the new alphanumeric format that includes letters (A-Z). Starting in July 2026, the alphanumeric format with letters will become the standard for all new CNPJ registrations in Brazil. Generated numbers follow official formatting rules and pass validation algorithms but are not associated with real companies.

Generate properly formatted CNPJ numbers with correct structure and validation digits in both numeric and alphanumeric (with letters) formats. The tool supports both formatted (XX.XXX.XXX/XXXX-XX) and unformatted output, with bulk generation capabilities for comprehensive testing scenarios in Brazilian business applications. Switch between traditional numeric CNPJs and the new alphanumeric CNPJs that include letters — which will be mandatory from July 2026.

Essential for testing Brazilian business applications, corporate registration systems, tax compliance testing, and development environments requiring valid CNPJ formats. Perfect for fintech, e-commerce, and business management system development targeting the Brazilian market. Especially important now to test compatibility with the new alphanumeric CNPJ format with letters, as it becomes the norm from July 2026.

All generated CNPJ numbers follow official formatting rules and pass standard validation algorithms for both numeric and alphanumeric formats. This ensures your applications handle Brazilian corporate identification data correctly during development phases while maintaining compliance with Brazilian business registration requirements. Preparing for the July 2026 transition to alphanumeric CNPJs with letters is critical for any system operating in the Brazilian market.

Key Features

  • Valid CNPJ format (XX.XXX.XXX/XXXX-XX)
  • Supports numeric and alphanumeric formats with letters (A-Z)
  • New alphanumeric CNPJ with letters — standard from July 2026
  • Follows official Brazilian formatting rules
  • Formatted and unformatted output
  • Bulk generation support
  • Safe for testing and development
  • No association with real companies

CNPJ Frequently Asked Questions

Are these real CNPJ numbers?

No, these are test CNPJ numbers generated for development and testing only. They follow the correct format and pass validation algorithms but are not assigned to real companies by the Brazilian Revenue Service.

What is the new alphanumeric CNPJ format with letters?

The Brazilian government introduced a new alphanumeric CNPJ format that includes letters (A-Z) alongside numbers (0-9), while keeping the same 14-character structure (XX.XXX.XXX/XXXX-XX). This change was necessary because Brazil was running out of numeric-only CNPJ combinations. Starting in July 2026, this alphanumeric format with letters will become the standard for all new CNPJ registrations.

When will the alphanumeric CNPJ with letters become mandatory?

The new alphanumeric CNPJ format with letters will become the standard from July 2026. After this date, all new CNPJ registrations will use the alphanumeric format. Existing numeric CNPJs will remain valid, but all systems must be prepared to handle CNPJs containing letters.

How do I switch between numeric and alphanumeric formats?

Use the 'Alphanumeric Format' toggle switch next to the 'Formatted' option. When enabled, the generator creates CNPJs containing letters and numbers. When disabled, it generates traditional numeric-only CNPJs.

Can I use these CNPJs for real business registration?

Absolutely not. Using fake CNPJs for real business registration, tax filings, or official purposes is illegal in Brazil and can result in serious legal consequences including fraud charges.

How does CNPJ validation work for the alphanumeric format with letters?

Alphanumeric CNPJ validation uses an adapted modulo 11 algorithm that assigns numeric values to letters (A=10, B=11, ..., Z=35) and digits (0-9). The system calculates two verification digits based on the first 12 characters using the same mathematical principles as numeric CNPJs.

What CNPJ numbers should I avoid in testing?

Avoid well-known test CNPJs and sequential numbers. Use our generator to create realistic test data that won't conflict with real business identifiers or cause validation issues. Make sure to test both numeric and alphanumeric formats with letters to ensure your system is ready for the July 2026 transition.

Do these CNPJs work with Brazilian tax software?

For validation testing, yes — they pass format and check digit validation for both numeric and alphanumeric formats. However, they will fail when attempting real tax operations or government system integration since they're not registered with actual businesses. Note that some older systems may not yet support CNPJs with letters, so this is a great way to test compatibility before the July 2026 deadline.

CNPJ Testing Best Practices

  • Never use real CNPJs in test environments
  • Validate CNPJ format and check digits in your applications
  • Test both numeric and alphanumeric (with letters) CNPJ formats
  • Prepare your systems for the July 2026 alphanumeric CNPJ standard
  • Use these numbers only for development and testing
  • Implement proper CNPJ masking in user interfaces for both formats
  • Ensure your validation logic accepts letters (A-Z) in CNPJ fields
  • Follow Brazilian data protection guidelines for CNPJ handling

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