Choosing your business activity codes (CNAE and IAE)

Terms used

• CNAE — The CNAE is Spain's statistical code for business activities, used in company statutes, the tax census and Social Security.
• IAE — The IAE is the activity tax, which uses its own list of headings (epígrafes) to classify what a business does.
• Epígrafes — The epígrafes are the individual headings in the IAE list, one for each type of activity.
• TGSS — The TGSS is the Social Security treasury, where employers register and where your main CNAE code is held.
• Declaración responsable — A declaración responsable is a signed notice to the town hall that you meet the rules, letting you open without waiting for a licence.
• Modelo 036 — The modelo 036 is the tax form for registering or changing your business details in the census; modelo 037 is its simplified version.
• Registro Mercantil — The Registro Mercantil is the public commercial register where companies and changes to their statutes are recorded.

Key rules

• Real activity: Your codes must fit what you actually do, not what is cheapest or easiest.
• Insurance rate: Your main CNAE code decides your employer accident and occupational-disease rate.
• Corporate purpose: The activity description in your statutes should cover every code you register.
• Two lists: CNAE and IAE are separate lists, so pick each one on its own.

The codes must match what you really do

Choose codes that describe your real activity. They affect your accident-insurance rate for employees, which licence your premises need, and whether grants or tax filings go smoothly. A wrong code can mean the wrong insurance rate, tax or census penalties, and trouble with licences or grants.

Two different lists

The CNAE is a statistical code. It appears in your company statutes, the tax census and Social Security. Spain is moving from the CNAE-2009 list to an updated CNAE-2025 list in stages, so check which version your forms ask for.

The IAE has its own list of headings (epígrafes) for the activity tax. It is not the same list as the CNAE, so a CNAE code does not tell you the IAE heading. Choose each from its own list.

How to pick them

1. Describe your main activity in one sentence: what you sell, to whom, and where the work happens.
2. Read the official CNAE descriptions and the tax agency's IAE heading notes. Match your main activity to the closest entry in each.
3. Check that your corporate purpose (the activity description in your statutes) covers the codes you chose. If it doesn't, widen the statutes before you register.

You can register more than one activity. Whether to register one or several is covered in the decision below.

Why the main CNAE code costs you money

Your main CNAE code, registered with Social Security (TGSS), sets the employer's accident and occupational-disease contribution. The rate comes from a table that assigns a percentage per code. Riskier work such as construction pays more than office work. The table is updated periodically, so check the current rate for your code.

Why it matters for licences

The type of premises and activity decides whether you need an opening licence, a classified-activity licence or only a simple notice to the town hall (a declaración responsable). Your code often feeds into that decision, but the rules differ by council. Ask your town hall before you sign a lease or start works.

If you need to change a code

Report the change to the tax agency on a census amendment form (modelo 036 or 037) and tell Social Security. If the change alters your corporate purpose, you also need a statute amendment before a notary, registered in the Registro Mercantil. The FAQ below covers the steps.

Choosing between options

Should you register one activity code or several?

• One main activity: Your company does one clear kind of work. Pick the CNAE code and IAE heading that match it in the official descriptions.

• A main activity plus others: Your company does more than one kind of work, or plans to soon. Register each one, and make sure the corporate purpose in your statutes covers all of them.

Choose the code that matches what the company really does most. That main CNAE code sets your workplace-accident insurance rate, and riskier work such as construction pays more than office work. A wrong code can mean wrong rates, census sanctions, or problems with licences and grants.

Frequently asked questions

Can I register more than one activity code for my company?

Yes, you can register several activity codes, but one of them is your main activity. The main CNAE code registered with Social Security is the one that sets your accident-insurance rate, so choose it carefully.

How do I change my activity code after the company is set up?

You change it with a modification census declaration (modelo 036 or 037) and tell Social Security about it. If the corporate purpose in your statutes no longer covers the new code, you also need a statute amendment before a notary and at the Registro Mercantil.

Does the activity code decide which municipal licence I need?

Partly, because the licence depends mainly on your type of premises and activity, which are often linked to the code. The code helps show whether you need an opening licence, a classified-activity licence or just a simple notice. Ask your town hall, as the rules vary by council.