How and When Can I Register as Self-Employed?

The transition to self-employment is one of the most significant steps in any professional’s career. However, beyond the commercial perspective, there is a complex web of legal, fiscal, and financial implications that must be analysed rigorously. In Spain, the self-employed ecosystem has undergone profound legislative changes in recent years, requiring constant updates to avoid penalties and optimise tax burdens.

At Numo Gestión, we understand that your time should be spent creating value, not deciphering the BOE (Official State Gazette). That is why we have prepared this technical analysis, detailing everything you need to know and how we manage it on your behalf.

1. The Legal Framework: What Does It Really Mean to Be Self-Employed?

According to Article 1 of Law 20/2007, the Statute of Self-Employment (LETA), the figure of the self-employed person is defined as someone who carries out an economic activity for profit, on a regular, personal, and direct basis, without being subject to an employment contract.

For this definition to be effective, four elements must be present, which case law and the Labour Inspectorate scrutinise closely:

Organisational Autonomy: Unlike employees, self-employed individuals decide their working hours, place of work, and methods. The absence of this autonomy could result in the classification of a “false self-employed person,” with serious consequences for the contracting company.

Regularity: This is the most contentious point. Although there is no legally fixed income threshold, Social Security usually considers any repeated activity over time as “regular.” If you issue invoices every month, even if they are small, it counts as regular activity.

Assumption of Risk: The self-employed person has no guaranteed salary; profits depend on the success of their management, and they personally bear any losses.

Profit Motive: The activity must be aimed at generating economic profit.

2. When Is Registration Obligatory?

The activity does not begin with the first sale but with administrative formalisation. This process has two fronts that must be perfectly coordinated.

A. Tax Registry Registration with the Tax Agency (AEAT)

This is done through Form 036 (ordinary) or 037 (simplified). Here, the fiscal “birth certificate” of your business is established:

• Selection of IAE (Economic Activities Tax): Classifies your activity. An incorrect choice may deprive you of deductions or assign obligations that do not apply.
• VAT Regime: Determines whether your activity is subject to, exempt from (e.g., training or medical services), or subject to the equivalence surcharge.
• Income Tax Estimation: Most self-employed individuals choose the Simplified Direct Estimation, but in some cases, Objective Estimation (modules) may be more advantageous, although it is gradually disappearing.

B. Registration with RETA (Social Security)

This must be completed within 60 calendar days before starting the activity. Under the new real-income contribution system (in force since 2023), you no longer choose a contribution base arbitrarily. You must provide a forecast of your annual net income.

How does Numo do it for you?
At Numo Gestión, we do more than fill out forms. We analyse your business model to select the most advantageous IAE code and calculate your initial contribution bracket. We submit forms 036/037 and register you with Social Security without you needing to visit an office.

3. Tax Obligations: Calendar and Submission Forms

Compliance with tax obligations is perhaps the heaviest burden for the self-employed. Missing deadlines can result in automatic surcharges of 5%, 10%, or even 20%.

Value Added Tax (VAT)

The self-employed person acts merely as an intermediary (collector) for the Tax Agency.

• Form 303 (Quarterly): A declaration where you deduct VAT on expenses (input VAT) from VAT on sales (output VAT).
• Form 390 (Annual Summary): An informative declaration summarising the entire year.

VAT Submission Dates:

• 1st Quarter: 1–20 April
• 2nd Quarter: 1–20 July
• 3rd Quarter: 1–20 October
• 4th Quarter and Annual: 1–30 January of the following year

Income Tax (IRPF)

This tax levies your net profit (Income – Deductible Expenses).

• Form 130 (Installment Payments): An advance payment of 20% of your profit against your annual income tax return. If over 70% of your invoices include withholding, you may be exempt.
• Income Tax Return (Form 100): The definitive settlement, filed between April and June of the following year.

Submission Dates for Form 130: Coincide exactly with VAT deadlines.

Withholdings for Third Parties (Forms 111 and 190)

If you rent premises or hire another professional or employee, you must withhold a portion of their invoice for payment to the Tax Agency.

• Form 190 (Annual): Summary of who you have withheld from.
• Form 111 (Quarterly): Payment of withholdings.

Essential Steps for Registration:

1. Real-Income Contribution System: Since 2023, contributions are calculated based on projected net income. Accurate forecasting is crucial to avoid unexpected adjustments the following year.
2. Form 036 or 037 (Tax Agency): Selection of IAE code, VAT regime, and income tax method.
3. Registration with the General Treasury of Social Security (TGSS): Must be completed up to 60 days before starting activity.

4. The New Contribution System and Adjustments

Since 2023, Social Security works similarly to the Tax Agency. Throughout the year, you pay a monthly contribution based on a forecast. At the end of the fiscal year, Social Security cross-checks data with the Tax Agency:

• If you earned less than forecasted: Excess contributions are automatically refunded.
• If you earned more than forecasted: You must pay the difference in a single instalment.

At Numo Gestión, we monitor your income quarterly. If we see you are earning more than expected, we advise adjusting your contribution bracket to prevent unpleasant surprises from claims of thousands of euros by the Treasury.

5. Managing Deductible Expenses: The Key to Savings

Not everything you purchase is deductible. For the Tax Agency to accept an expense, it must meet three criteria:

1. Be linked to your economic activity.
2. Be properly documented (full invoice; receipts alone are insufficient).
3. Be recorded in the accounting books.

Certain expenses are complex, such as vehicle use (only 100% deductible for transport activities) or household utilities (if working from home, only 30% of the proportional area used can be deducted).

The self-employment landscape is moving towards full digitalisation, where Verifactu comes into play.

What is Verifactu?
It is the regulation developed under the Anti-Fraud Law requiring invoicing systems to meet security, integrity, and traceability standards. Essentially, the Tax Agency wants invoices to be generated in systems that prevent modification or deletion without leaving a trace. Numo helps your company become compliant before 2027.

6. At Numo, We Take Care of Everything

Administrative management for self-employed individuals in Spain is among the most complex in Europe. Attempting to manage it alone often results in errors that the Tax Agency will eventually detect.

What exactly do we do at Numo?

• Personal Advisor Assignment: You have an expert familiar with your case, not a generic “chatbot.”
• Submission of All Forms: We file your 303, 130, 111, 390, and 190 forms. You only receive the submission confirmation.
• Mandatory Accounting Books: We maintain your records of issued and received invoices, and fixed assets, in accordance with regulations.
• Invoice Digitalisation: Forget shoeboxes full of papers. Our system digitises and organises all invoices.
• Monitoring Notifications: We are connected to the DEHú (Single Enabled Electronic Address) to receive any communications from the Administration and respond on time, avoiding penalties for non-response.