Conversor IAE CNAE

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Spanish IAE/CNAE tax activity codes, 2009→2025 crosswalk and AEAT obligations.

About Conversor IAE CNAE

Conversor IAE CNAE is a lookup and conversion tool for Spanish tax activity codes, providing official correspondence between IAE (Impuesto sobre Actividades Economicas) epigraphs and CNAE 2025 classification codes. The database is sourced from AEAT and INE and covers 2,876 cross-referenced codes, allowing bidirectional search by code or by describing an economic activity. It is aimed at autonomos (self-employed workers), gestorias, and tax advisory firms handling filings such as modelo 036, and includes tools for verifying whether a CNAE code migrated correctly to the 2025 revision.

The site also provides an API for developers building ERPs, digital gestoria platforms, or fintech onboarding flows that need IAE/CNAE/AEAT classification data, with a free tier of 250 requests per day and a paid tier at 29 euros per month. An MCP server is offered for connecting AI agents (such as Claude, ChatGPT, Cursor, or Gemini CLI) to the same official data for querying IAE epigraphs, CNAE 2025 codes, tax deadlines, and RETA contribution rates.

Additional resources include a modulos IRPF calculator, an autonomo registration assistant for identifying the correct codes for modelo 036, RETA, IRPF, and IVA filings, and a blog with guides on CNAE 2025, IAE, and related tax procedures.

Key features

Bidirectional IAE ↔ CNAE 2025 code conversion with search by code or activity name
Database of 2,876 official codes cross-referenced from AEAT and INE
CNAE 2025 migration verifier to check if a code updated correctly
REST API for IAE/CNAE/AEAT data with free tier of 250 requests/day
MCP server for AI agents (Claude, ChatGPT, Cursor, Gemini CLI) to query fiscal codes
IRPF módulos calculator for autónomos under estimación objetiva

Frequently asked questions

Is there a free tier for the API?

Yes, the API offers a free tier of 250 requests/day, with a Professional plan at 29 €/month for higher usage.

What data sources back the code conversions?

The database is built from official AEAT (Spanish Tax Agency) and INE (national statistics institute) sources, covering 2,876 cross-referenced codes.

Who is this tool for?

It targets autónomos (self-employed workers), gestorías, asesorías fiscales, and developers building ERPs, fintech onboarding, or digital gestoría software.

Can AI agents like Claude or ChatGPT access this data?

Yes, the site provides an MCP server with 18 free tools, requiring no API key or registration, that connects AI agents to official AEAT, INE, and BOE fiscal data.

Does the tool help with the CNAE 2025 migration deadline?

Yes, it includes a CNAE 2025 verifier to check if a code migrated correctly and flags the general one-month deadline (modelo 036) for reporting to Hacienda.