The Ultimate Guide to Spanish Tax Forms (2025): Everything Small Businesses & Freelancers Need to Know

Spain’s tax system is known for its complexity, especially when it comes to filing requirements. Whether you’re running a small company or working as a freelancer, getting your head around the various forms is essential for compliance and peace of mind.

This guide walks you through the key tax declarations for 2025—when to file them, who needs to file them, and why they matter. If you’re managing operations in Spain, this post will help you master the requirements.

The Breadth of Spanish Tax Filings

According to a consultancy report, Spain has over 140 tax declaration types, with 45 being purely informative—meaning no tax is due. A typical small business may need to file 15–22 forms annually depending on its activity levels and involvement in European transactions. Larger companies may upload more than 30 filings annually. 

Late or incorrect filings can trigger fines or require extra steps, so staying organized is not optional—it’s vital.

Business Registration Forms: M036 & M037

• M036 is the comprehensive form used to register, deregister, or modify business details across various tax regimes.
• M037 serves as a streamlined version, best suited for simpler business structures like sole proprietorships. 

These act as your start line—filing accurately ensures all subsequent declarations link correctly to your entity.

Income Tax Declaration (Modelo 100)

• For individuals—both employees and self-employed—the Modelo 100 is the annual personal income tax return filed between April and June.
• Some are exempt:
  • Single-employer employees with income under €22,000 (not for foreign income).
  • Multi-source taxpayers earning less than €15,000, such as pensioners.
• However, filing even when exempt can lead to refunds if taxes were withheld. 

Important: Self-employed individuals must file – exemption doesn’t apply to them.

Self-Employed Quarterly Obligations

If you’re self-employed (autónomo), you’ll deal with multiple periodic forms:

• Modelo 130 – Quarterly income tax prepayment (IRPF), usually calculated on your net profit. You can opt for a flat 20% rate and get a benefit allowance of 7% (up to €2,000).
• Modelo 111 – Withholding tax on invoices issued to businesses. Normally 15%, reduced to 7% for newly registered self-employed during the first three years.
• Modelo 115 – Withholding on rental payments (19%) remitted by the tenant.
• Modelo 303 – Quarterly VAT (IVA) return. Standard rate is 21%, with reduced (10%) or super-reduced exemptions (4%). Submit quarterly and use Modelo 390 for the annual summary. 
• Modelo 347 – Annual disclosure of operations exceeding €3,005.06 with any single party. Required for transparency and enforcement. 

Filing Deadlines and Publication Practices

• For VAT and withholding (Forms 111, 115, 130, 303):
  • Q1: April 20
  • Q2: July 20
  • Q3: October 20
  • Q4: January 20 (IRPF/VAT) or January 30 (VAT extension)
• Modelo 390 (annual VAT summary) and Modelo 347 are generally due by end of February.

Note: Filing must be done online. If your tax payment is involved, it should be lodged at least 5 business days before the deadline; otherwise you’ll need an NRC (bank reference code) to complete payment.

Context: Self-Employed vs Incorporated Business

Choosing between self-employed or an SL structure depends on liability concerns, expense deduction flexibility, and tax efficiency.

Why Timely and Accurate Compliance Matters

• Avoid fines and administrative penalties.
• Manage cash flow without unexpected late payments.
• Optimize tax credits and refunds—especially when withholding or VAT credits are involved.
• Audit readiness through consistent reporting (e.g., with Modelo 347).
• Peace of mind in a system with layered bureaucracy and regional variation.
  
  

How Taxadora Helps You Stay on Track

We support entrepreneurs and freelancers by:

• Identifying all required forms for your business profile.
• Preparing and submitting filings accurately and on time.
• Clarifying applicable exemptions and deductions.
• Resolving emergencies like filing mistakes or deadline oversights.

Final Takeaway

Spain’s tax form system can feel overwhelming—but with clarity, Preparation, and organization, you can master it. Whether you file 5 or 25 forms a year, understanding deadlines, exemptions, and form relevance is your path to compliance and financial control.