Selling Online in Spain? The Taxman May Already Have Your Details

Tax Season Is Open — And They're Watching

Spain's income tax return season has officially opened on April 8, and this year the Agencia Tributaria is paying particularly close attention to people earning money through online platforms.

If you've been selling on Wallapop, Vinted, eBay or Milanuncios, it's worth understanding where you stand — because the taxman may already know more about your activity than you think.

The Key Thresholds

Platforms are now legally required to report sellers who hit either of these figures to the Spanish tax authorities:

• 30 transactions per year, or
• €2,000 in total sales value

If you've crossed either threshold, the Agencia Tributaria likely already has a clear picture of your activity before you even sit down to file.

3.56 Million Reminder Notices

The tax agency is sending out 3.56 million reminder notices to taxpayers this year, covering:

• 437,000 notices relating to income from digital platforms — selling goods, providing services, or renting through apps
• 1.24 million notices for cryptocurrency traders — the agency already holds data on balances, transfers and exchanges
• Notices for holiday rental landlords — with data on rental days, commissions and amounts withheld by platforms

How the Notices Work

The notices arrive in three stages:

1. When you download your tax data — flagging income that needs declaring
2. During filing — warning you about potential errors or omissions
3. After filing — pointing out discrepancies between what you declared and what the agency already knows

The good news: nearly half of taxpayers who receive a notice go on to correct their return voluntarily, avoiding the heavier penalties that follow a formal investigation.

Crypto and Holiday Rentals Too

Cryptocurrency: If you hold virtual currencies abroad worth over €50,000, the deadline for filing Form 721 was March 31. If you missed it, get advice quickly.

Holiday rentals: The agency has full access to data from rental platforms. On the upside, landlords renting to permanent residents in high-demand areas could be eligible for reductions of up to 90% of net rental income if they've reduced their price by 5%.

The Bottom Line

If you've been selling online, trading crypto or renting out property through apps in Spain, assume the tax agency already knows about it. File accurately, declare everything, and correct any errors before they find them for you.

This article is based on reporting from Alicante Today, published April 13, 2026. This article is for informational purposes only and does not constitute tax advice. Always consult a qualified tax professional.